Truffle trouble: what happened to the Tuberales?
Truffle trouble: what happened to the Tuberales?
Truffle trouble: what happened to the Tuberales?
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<strong>Truffle</strong> <strong>trouble</strong>: <strong>what</strong> <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>?<br />
Thomas LÆSSØE a, *, Karen HANSEN b,y<br />
a Department of Biology, Copenhagen University, DK-1353 Copenhagen K, Denmark<br />
b Harvard University Herbaria – Farlow Herbarium of Cryp<strong>to</strong>gamic Botany, Cambridge, MA 02138, USA<br />
article info<br />
Article his<strong>to</strong>ry:<br />
Received 10 February 2006<br />
Received in revised form<br />
27 April 2007<br />
Accepted 9 August 2007<br />
Published online 25 August 2007<br />
Corresponding Edi<strong>to</strong>r: Scott LaGreca<br />
Keywords:<br />
Ascomycota<br />
Helvellaceae<br />
Hypogeous<br />
Pezizaceae<br />
Pezizales<br />
Pyronemataceae<br />
Introduction<br />
abstract<br />
Fungi pursuing <strong>the</strong> truffle strategy by producing underground<br />
sporocarps have long been recognized as a polyphyletic group<br />
with representatives in <strong>the</strong> former Zygomycota now Glomeromycota<br />
(Endogone, Glomus a.o.), Ascomycota, and Basidiomycota.<br />
Those with asci were at one time all placed in <strong>the</strong> <strong>Tuberales</strong><br />
(e.g. Tulasne & Tulasne 1851; Fischer 1897; Knapp 1950;<br />
Hawker 1954; Eckblad 1968; Korf 1973a). Nannfeldt (1946)<br />
wrote: ‘The question is raised whe<strong>the</strong>r Tuberineae is monophyletic<br />
or whe<strong>the</strong>r it is composed of different operculates<br />
that have evoluted convergently in<strong>to</strong> hypogeous forms.’<br />
mycological research 111 (2007) 1075–1099<br />
journal homepage: www.elsevier.com/locate/mycres<br />
An overview of truffles (now considered <strong>to</strong> belong in <strong>the</strong> Pezizales, but formerly treated in<br />
<strong>the</strong> <strong>Tuberales</strong>) is presented, including a discussion on morphological and biological traits<br />
characterizing this form group. Accepted genera are listed and discussed according <strong>to</strong> a system<br />
based on molecular results combined with morphological characters. Phylogenetic<br />
analyses of LSU rDNA sequences from 55 hypogeous and 139 epigeous taxa of Pezizales<br />
were performed <strong>to</strong> examine <strong>the</strong>ir relationships. Parsimony, ML, and Bayesian analyses of<br />
<strong>the</strong>se sequences indicate that <strong>the</strong> truffles studied represent at least 15 independent lineages<br />
within <strong>the</strong> Pezizales. Sequences from hypogeous representatives referred <strong>to</strong> <strong>the</strong> following<br />
families and genera were analysed: Discinaceae–Morchellaceae (Fischerula, Hydnotrya,<br />
Leucangium), Helvellaceae (Balsamia and Barssia), Pezizaceae (Amylascus, Cazia, Eremiomyces,<br />
Hydnotryopsis, Kaliharituber, Mattirolomyces, Pachyphloeus, Peziza, Ruhlandiella, Stephensia,<br />
Terfezia, and Tirmania), Pyronemataceae (Genea, Geopora, Paurocotylis, and Stephensia) and<br />
Tuberaceae (Choiromyces, Dingleya, Labyrinthomyces, Reddellomyces, and Tuber). The different<br />
types of hypogeous ascomata were found within most major evolutionary lines often nesting<br />
close <strong>to</strong> apo<strong>the</strong>cial species. Although <strong>the</strong> Pezizaceae traditionally have been defined<br />
mainly on <strong>the</strong> presence of amyloid reactions of <strong>the</strong> ascus wall several truffles appear <strong>to</strong><br />
have lost this character. The value of <strong>the</strong> number of nuclei in mature ascospores as a delimiting<br />
family character is evaluated and found <strong>to</strong> be more variable than generally assumed.<br />
ª 2007 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.<br />
Malençon (1938) also advanced ideas about <strong>the</strong> evolution of<br />
truffles and <strong>the</strong>ir transformation from epigeous apo<strong>the</strong>cial<br />
species <strong>to</strong> hypogeous truffles, but, as pointed out by Burdsall<br />
(1968), his system relied <strong>to</strong>o heavily on macroscopic features.<br />
Korf (1973b) discussed <strong>the</strong> evolution of convoluted pezizalean<br />
forms, both above and below ground, and although he accepted<br />
<strong>the</strong> <strong>Tuberales</strong>, he indicated that at least some of <strong>the</strong><br />
taxa were derived along various evolutionary lines within<br />
<strong>the</strong> Pezizales. He considered <strong>Tuberales</strong> <strong>to</strong> be a biological unit<br />
ra<strong>the</strong>r than a phylogenetic one. Trappe (1971) published a similar<br />
statement, and finally Trappe (1979), proposed that <strong>the</strong><br />
order be abandoned, with one major part being moved <strong>to</strong> <strong>the</strong><br />
* Corresponding author.<br />
E-mail address: thomasl@bi.ku.dk<br />
y<br />
Present Address: Swedish Museum of Natural His<strong>to</strong>ry, Cryp<strong>to</strong>gamic Botany, Box 50007, SE-10405 S<strong>to</strong>ckholm, Sweden.<br />
0953-7562/$ – see front matter ª 2007 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.<br />
doi:10.1016/j.mycres.2007.08.004
1076 T. Læssøe, K. Hansen<br />
Pezizales and just Elaphomyces <strong>to</strong> <strong>the</strong> Elaphomycetales. Fischer<br />
(1897) had earlier referred Elaphomyces <strong>to</strong> <strong>the</strong> ‘Plectascineae’<br />
but alongside <strong>the</strong> Terfeziaceae. Later (Fischer 1938), Terfeziaceae<br />
reappeared within <strong>the</strong> <strong>Tuberales</strong>. Trappe (1979) kept some hypogeous<br />
lines, as families, within his Pezizales, but o<strong>the</strong>r hypogeous<br />
taxa were placed alongside epigeous species in various<br />
mixed families. Burdsall (1968) had already convincingly<br />
merged one tuberalean genus (Geopora) with <strong>the</strong> pezizalean<br />
genus Sepultaria. Eckblad (1968) gave many clear arguments<br />
for not accepting <strong>the</strong> <strong>Tuberales</strong> but, never<strong>the</strong>less, concluded<br />
<strong>the</strong> opposite. In <strong>the</strong> first Outline of <strong>the</strong> Ascomycetes (Eriksson<br />
1982) <strong>Tuberales</strong> (with Geneaceae, Terfeziaceae, and Tuberaceae)<br />
were relegated <strong>to</strong> synonymy of Pezizales. Ainsworth & Bisby’s<br />
Dictionary of <strong>the</strong> Fungi (Hawksworth 1983) likewise abandoned<br />
<strong>the</strong> use of <strong>Tuberales</strong> and listed <strong>the</strong> order under Pezizales (and<br />
Elaphomycetales). Trappe’s hypo<strong>the</strong>sis was tested in a longlasting<br />
study of <strong>the</strong> ultrastructure of pezizalean taxa guided<br />
by Kimbrough and summarized in Kimbrough (1994), that<br />
for example, led <strong>to</strong> <strong>the</strong> placement of Hydnobolites in <strong>the</strong> Pezizaceae,<br />
based on both cy<strong>to</strong>logical and ultrastructural features of<br />
asci and ascospores. Also <strong>the</strong> placement of Barssia in <strong>the</strong> Helvellaceae<br />
followed from <strong>the</strong>se studies. The most important<br />
character used was <strong>the</strong> morphology of <strong>the</strong> complicated septal<br />
pore-apparatus at <strong>the</strong> base of <strong>the</strong> asci (Kimbrough 1994). Ano<strong>the</strong>r<br />
prominent feature, <strong>the</strong> number of nuclei in <strong>the</strong> mature<br />
spores that originated in Ber<strong>the</strong>t’s (1963) studies on epigeous<br />
Pezizales, was also taken in<strong>to</strong> account when trying <strong>to</strong> delimit<br />
natural groups of truffles (e.g. Ber<strong>the</strong>t 1982; Donadini 1986a,<br />
b). With <strong>the</strong> onset of <strong>the</strong> molecular taxonomy era, <strong>the</strong>se early<br />
hypo<strong>the</strong>ses have gradually been confirmed and expanded<br />
upon, or in some cases, corrected (e.g. O’Donnell et al. 1997;<br />
Norman & Egger 1999; Percudani et al. 1999; Hansen et al.<br />
2005; Perry et al. 2007). In a comprehensive treatment of European<br />
(mainly Italian) truffles Montecchi & Sarasini (2000) refer<br />
former <strong>Tuberales</strong> taxa <strong>to</strong> Elaphomycetales, with just Elaphomyces,<br />
and Pezizales with seven families: Pezizaceae (four genera),<br />
Pyronemataceae (four genera), Geneaceae (two genera), Helvellaceae<br />
(three genera), Balsamiaceae (two genera), Terfeziaceae<br />
(four genera) and Tuberaceae with two genera. Although, <strong>the</strong>y<br />
cite recent molecular results, <strong>the</strong>y have chosen a conservative<br />
approach by following <strong>the</strong> systems proposed in Trappe (1979)<br />
and Pegler et al. (1993). One group of researchers (Parguey-<br />
Leduc et al. 1987b, 1990; Janex-Favre & Parguey-Leduc 2003)<br />
proposed <strong>to</strong> accept <strong>Tuberales</strong> based mainly on <strong>the</strong> genera Tuber<br />
and Terfezia that were considered closely related, mostly<br />
based on a perceived different development of asci and ascospores.<br />
van Brummelen (1994) gave a summary of <strong>the</strong> arguments<br />
put forward up <strong>to</strong> that time. Eriksson (2006b),<br />
influenced by data published by e.g. de Hoog et al. (2005), discussed<br />
<strong>what</strong> <strong>to</strong> do nomencla<strong>to</strong>rily if Pezizales are restricted<br />
<strong>to</strong> Pezizaceae. Although <strong>Tuberales</strong> are a possible choice, he proposed<br />
<strong>to</strong> find ano<strong>the</strong>r name. Currently, however, <strong>the</strong>re is no<br />
supported molecular phylogenetic evidence that suggests<br />
Pezizaceae are not part of <strong>the</strong> Pezizales (<strong>the</strong> Pezizaceae are supported<br />
as monophyletic by a BS value of 100 %, but <strong>the</strong> relationships<br />
among <strong>the</strong> included families in e.g. de Hoog et al.<br />
(2005) are without support).<br />
The purpose of this paper is <strong>to</strong> review morphological and biological<br />
traits, and <strong>the</strong> systematics of <strong>the</strong> passively dispersed,<br />
more or less hypogeous Pezizales. Using all currently available<br />
LSU sequences from pezizalean truffles, in analyses with<br />
a broad sample of epigeous pezizalean taxa, we will fur<strong>the</strong>r investigate<br />
<strong>the</strong> phylogenetic relationships and evolution of <strong>the</strong>se<br />
truffle fungi. Ascomyce<strong>to</strong>us truffles, which are now considered<br />
<strong>to</strong> be non-pezizalean (Elaphomyces, Eurotiomycetes), are not<br />
treated in detail. The taxonomic position of all accepted taxa<br />
at and above generic level are given and compared with previous<br />
classifications. The accepted classification is based on molecular<br />
phylogenetic analyses and morphological characters.<br />
A truffle definition<br />
Ascomycete truffles can be defined as producing sporocarps<br />
below or at ground level and with a simultaneous loss of active<br />
spore dispersal. In several genera, for example Geopora and<br />
Helvella, species with intermediate characters can be found.<br />
Also Sarcosphaera coronaria is an example of a fungus that<br />
has nearly become a truffle. It forms apo<strong>the</strong>cia below ground<br />
and often opens by a ra<strong>the</strong>r small aperture, but as <strong>the</strong> spores<br />
are actively ejected it can still be classified as a ‘‘cup fungus’’.<br />
The genus Caulocarpa was based on such hypogeous Sarcosphaera<br />
ascomata (Trappe 1975c). Although some species tend<br />
<strong>to</strong> produce sporocarps in or on <strong>the</strong> litter, we still group <strong>the</strong>m<br />
with <strong>the</strong> truffles as long as <strong>the</strong>y have lost active spore dispersal.<br />
Glaziella and Paurocotylis are good examples.<br />
Morphological features of pezizalean truffles<br />
The ascomata are typically fleshy but can be quite hard and<br />
cartilaginous. An outer rind (peridium) is often present and<br />
can be almost woody and sculptured. Even at maturity <strong>the</strong><br />
spores do not become powdery, except in a few genera (e.g.<br />
Carbomyces) that are adapted <strong>to</strong> extreme xeric conditions.<br />
There is a continuous variation from truffles with a single cavity<br />
lined with a hymenium, often with a single opening, <strong>to</strong><br />
truffles with intricate foldings or with pockets of asci in<br />
a firm gleba. Weber et al. (1997) defined three different types<br />
of hypogeous ascomata within <strong>the</strong> Pezizales: ptycho<strong>the</strong>cia<br />
with persistent, recognizable hymenia and variously folded<br />
or even solid ascomata; stereo<strong>the</strong>cia without hymenia and<br />
solid ascomata; and exo<strong>the</strong>cia with external hymenia. None<br />
of <strong>the</strong>se ascoma types can accommodate Paurocotylis and<br />
Glaziella. These genera produce ascomata that are hollow,<br />
without paraphyses, and fur<strong>the</strong>rmore, are unusual in being<br />
fully exposed at maturity. Hansen et al. (2001) reviewed <strong>the</strong><br />
morphological features of <strong>the</strong> truffles considered <strong>to</strong> belong<br />
<strong>to</strong> <strong>the</strong> Pezizaceae. Those pezizalean species that have been<br />
studied in on<strong>to</strong>genic detail, such as Tuber and Terfezia species<br />
(Janex-Favre & Parguey-Leduc 2003), start out as apo<strong>the</strong>cial<br />
before folding occurs. The asci can at one end of <strong>the</strong> variation<br />
resemble those of operculate species being cylindrical with<br />
spores in one row or at <strong>the</strong> o<strong>the</strong>r end be completely globose<br />
with or without a pedicel and with a variable number of often<br />
very large spores. The ascospores vary in colour from hyaline<br />
<strong>to</strong> almost black, and in surface features from smooth and<br />
thin-walled <strong>to</strong> very thick-walled with intricate ornamentation.<br />
The ascus walls can be more or less layered and amyloid<br />
or inamyloid. The Pezizaceae are characterized by amyloid asci,<br />
but this feature appears <strong>to</strong> have been lost in many pezizaceous<br />
truffles (Hansen et al. 2001, 2005).
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1077<br />
<strong>Truffle</strong> identification and nomenclature<br />
Castellano et al. (1989) have published a slightly dated key <strong>to</strong><br />
<strong>the</strong> spores of genera found in north temperate forests. An<br />
updated key, taking fur<strong>the</strong>r characters in<strong>to</strong> use, can be found<br />
on <strong>the</strong> Internet (http://natruffling.org/ascokey.htm), and an<br />
earlier printed version was published by Trappe & Castellano<br />
(1992). Trappe’s (1979) synoptical key is still useful. In Europe<br />
two main illustrated accounts with keys are current<br />
(Montecchi & Sarasini 2000; Pegler et al. 1993). O<strong>the</strong>r important<br />
contributions include Lange (1956), Lawrynowicz (1988), and<br />
Montecchi & Lazzari (1993).<br />
The names of pezizalean truffles are given sanctioned status<br />
if included in Fries (1821–1832) and should be used when<br />
available for a given taxon. In practice, however, ano<strong>the</strong>r tradition<br />
has evolved, where Vittadini’s (1831) much more accurate<br />
work on European truffles has been used as <strong>the</strong> de fac<strong>to</strong><br />
starting point for especially Tuber nomenclature. As Trappe<br />
(2001) has pointed out, it will be necessary <strong>to</strong> propose <strong>the</strong>se<br />
Vittadini names for conservation over <strong>the</strong> sanctioned Friesian<br />
names in order not <strong>to</strong> disrupt <strong>the</strong> very long usage of <strong>the</strong>se<br />
names for such economically important organisms.<br />
Distribution, diversity, and dispersal<br />
Although, false truffles (hypogeous Basidiomycota) have been<br />
collected in extreme arctic environments, <strong>the</strong> true truffles<br />
would appear <strong>to</strong> have a more limited distribution, with a clear<br />
peak in diversity in temperate–subtropical, often ra<strong>the</strong>r dry<br />
climates. Although a high number of publications are dedicated<br />
<strong>to</strong> truffles, a reasonable picture of <strong>the</strong> diversity and distribution<br />
of <strong>the</strong> group has still not been achieved. Castellano<br />
et al. (2004) from one long Australian study suggest a figure<br />
of 600 species (although mainly of false truffles), most of<br />
which remain <strong>to</strong> be described. A part of this project was described<br />
in Claridge et al. (2000). Only ten of <strong>the</strong>se species belong<br />
<strong>to</strong> <strong>the</strong> Ascomycota, and two apparently <strong>to</strong> undescribed<br />
genera. [See also <strong>the</strong> extensive review of Australian and New<br />
Zealand sequestrate fungi by Bougher & Lebel (2001).] Only<br />
Europe and parts of North America can be claimed <strong>to</strong> be<br />
reasonably well covered with respect <strong>to</strong> hypogeous fungi<br />
(Castellano et al. 2004). Distributions of European taxa are<br />
dealt with in Lawrynowicz (1991). Parts of Asia would seem<br />
<strong>to</strong> be equally rich in truffles. Africa and South America are apparently<br />
especially poor in hypogeous ascomycetes but be<br />
aware of <strong>the</strong> likely differences in sampling efforts in various<br />
regions. Verbeken & Walleyn (2003) in a checklist of subsaharan<br />
sequestrate fungi only reported one pezizalean species,<br />
Terfezia decaryi from Madagascar. In addition, three species are<br />
known from <strong>the</strong> sou<strong>the</strong>rn dry lands of continental Africa,<br />
including <strong>the</strong> Kalahari (Marasas & Trappe 1973; Ferdman<br />
et al. 2005). Two were separated as new genera (Ferdman<br />
et al. 2005). The third, Terfezia austroafricana, was listed as<br />
a member of Terfezia subgen Mattirolomyces and may require<br />
a new combination, as Mattirolomyces has been raised <strong>to</strong> generic<br />
rank. Although <strong>to</strong>o little is known, it is fairly clear that<br />
many localized endemics are <strong>to</strong> be found among pezizalean<br />
truffles.<br />
It has been hypo<strong>the</strong>sized that all, or nearly all, truffles are<br />
passively dispersed with animal vec<strong>to</strong>rs, but <strong>the</strong>re is very little<br />
experimental evidence <strong>to</strong> support this assertion. Various<br />
small mammals, including Australian marsupials (e.g.<br />
Claridge & May 1994), and voles and chipmunks in North<br />
America, collect and often hoard ascomata and by this activity<br />
are thought <strong>to</strong> play an active dispersal role (e.g. Fogel & Trappe<br />
1978; Maser et al. 1978). The s<strong>to</strong>mach contents of voles and<br />
chipmunks have been found <strong>to</strong> contain over 70 % truffles. So<br />
far it has not been shown that pezizalean truffle spores can<br />
germinate after gut passage but in all likelihood <strong>the</strong>y can.<br />
The volatile compounds truffles exude when ripe clearly substantiate<br />
<strong>the</strong> claim that <strong>the</strong>se mammals are <strong>the</strong> key dispersal<br />
vec<strong>to</strong>rs. Also larger mammals such as boar and deer are well<br />
known for <strong>the</strong>ir ability <strong>to</strong> locate and digest truffles, and presumably,<br />
also act in a beneficial way <strong>to</strong> <strong>the</strong> truffles by <strong>the</strong>ir<br />
dispersal abilities. The volatile compounds may resemble<br />
pheromones (Claus et al. 1981) and can also be used in species<br />
recognition (e.g. Marin et al. 1984; Pacioni et al. 1990). Trappe<br />
(1977) and Trappe et al. (2001) have speculated that <strong>the</strong> ec<strong>to</strong>mycorrhizal<br />
truffle partners migrated along with <strong>the</strong> rodent<br />
dispersers and <strong>the</strong> truffles <strong>the</strong>mselves, many populations<br />
later becoming isolated as a result of continental drift. Many<br />
invertebrates (Diptera etc) also actively seek out truffles, but<br />
although a more parasitic aspect <strong>to</strong> this relationship can be<br />
postulated, additional dispersal ability cannot be ruled out.<br />
Even birds have been claimed <strong>to</strong> actively seek out truffles<br />
and possibly act as dispersal vec<strong>to</strong>rs (Alsheikh & Trappe<br />
1983b; Castellano et al. 2004). One example concerns <strong>the</strong> desert<br />
truffle Phaeangium (or Picoa) lefebvrei, which is believed <strong>to</strong> be<br />
dispersed by various species of desert-adapted larks, but<br />
also by cream-coloured courser and hoopoe. Ano<strong>the</strong>r case<br />
deals with Paurocotylis pila, which at maturity has epigeous,<br />
orange–red fruit bodies coinciding with <strong>the</strong> fall of likewise<br />
bright-coloured Podocarpus fruits, known <strong>to</strong> be bird dispersed.<br />
Whe<strong>the</strong>r birds may also be involved in <strong>the</strong> dispersal of introduced<br />
British populations of Paurocotylis is not known.<br />
Material and methods<br />
Taxon sampling and alignment<br />
To summarize and determine <strong>the</strong> phylogenetic placement of<br />
hypogeous taxa within Pezizales, LSU rDNA sequences from<br />
48 hypogeous species (represented by 55 specimens) and 134<br />
epigeous pezizalean species (represented by 141 specimens)<br />
were compiled for analyses (for sequence accession numbers,<br />
see online Supplementary Data Table 1). Sequences were selected<br />
<strong>to</strong> represent all sub-lineages within Pezizales based primarily<br />
on Hansen et al. (2001, 2005), O’Donnell et al. (1997), and<br />
Perry et al. (2007). Nucleotide sequences were aligned by hand<br />
using <strong>the</strong> software program Se-Al v. 2.0a11 (Rambaut 1996<br />
Se-Al: Sequence Alignment Edi<strong>to</strong>r; available at http://evolve.<br />
zoo.ox.ac.uk/). The LSU rDNA contains highly divergent regions<br />
across all of <strong>the</strong> Pezizales. Therefore, three subset<br />
alignments were constructed, each representing one of three<br />
distinct lineages identified within <strong>the</strong> Pezizales (Fig 1)(Landvik<br />
et al. 1997; Hansen & Pfister 2007). The three alignments include<br />
representative taxa from <strong>the</strong> families Pezizaceae (lineage<br />
A; Fig 2); Caloscyphaceae, Discinaceae, Helvellaceae, Morchellaceae,<br />
Rhizinaceae, and Tuberaceae (lineage B; Fig 3); and
1078 T. Læssøe, K. Hansen<br />
A<br />
Ascodesmidaceae and Pyronemataceae (lineage C; Fig 4). Members<br />
of <strong>the</strong> Sarcoscyphaceae and Sarcosomataceae were not included,<br />
because no truffle taxa were affiliated with <strong>the</strong>se families.<br />
The final datasets included 68 epigeous species (from 72 specimens)<br />
and 17 hypogeous species (20 specimens) (lineage A); 22<br />
epigeous species (one specimen each) and 22 hypogeous species<br />
(23 specimens) (lineage B); and 44 epigeous species (47<br />
specimens) and nine hypogeous species (12 specimens) (lineage<br />
C). Based on phylogenetic analyses of higher-level relationships<br />
(e.g. Landvik 1996; Hansen & Pfister 2007; Perry et al.<br />
2007), Neolecta vitellina was used as an outgroup for lineage A<br />
(with <strong>the</strong> ingroup also including taxa from <strong>the</strong> lineages B and<br />
C); two species of Peziza and Iodophanus for lineage B; and Ascobolus<br />
and Peziza for lineage C. Alignments are available from<br />
TreeBASE (http://www.treebase.org) as accessions M3364 (lineage<br />
A), M3363 (lineage B), and M3362 (lineage C).<br />
Phylogenetic analyses<br />
B<br />
Pyronemataceae<br />
Sarcoscyphaceae<br />
Sarcosomataceae<br />
Morchellaceae-Discinaceae<br />
Analyses of <strong>the</strong> LSU were performed using PAUP version<br />
4.0b10 for Unix (Swofford 2002) and MrBayes 3.0b4 (Huelsenbeck<br />
& Ronquist 2001) on G5 Macin<strong>to</strong>sh computers. MP, parsimony<br />
BS (PB), and Bayesian analyses were performed as in<br />
C<br />
Helvellaceae-Tuberaceae<br />
Rhizinaceae<br />
Caloscyphaceae<br />
Pezizaceae<br />
Ascobolaceae<br />
Ascodesmidaceae<br />
Glaziellaceae<br />
Fig 1 – Schematic tree giving an overview of <strong>the</strong> three major<br />
clades (A–C) identified within Pezizales using SSU rDNA<br />
sequences (after Landvik et al. 1997). <strong>Truffle</strong>s have evolved<br />
within <strong>the</strong> families highlighted in bold. Families listed for<br />
each clade follow Eriksson (2006a). The Morchellaceae–<br />
Discinaceae and Helvellaceae–Tuberaceae lineages are<br />
according <strong>to</strong> O’Donnell et al. (1997).<br />
Hansen et al. (2005), except Bayesian MCMC were run for 5M<br />
generations. The GTR þ I þ G model of sequence evolution<br />
was selected for each dataset using MrModeltest v. 2.2<br />
(Nylander 2004). In Bayesian analyses, <strong>the</strong> first 1500 trees<br />
were deleted as <strong>the</strong> ‘burn-in’ period of <strong>the</strong> chain for <strong>the</strong> lineage<br />
A dataset, and Bayesian PP are based on <strong>the</strong> last 48,500 trees<br />
sampled. For <strong>the</strong> lineages B and C, <strong>the</strong> last 46,700 and 49,000<br />
trees were used, respectively. Clades represented by<br />
PB 75 % and/or PP 95 % are considered <strong>to</strong> be significantly<br />
supported.<br />
Based upon <strong>the</strong> results of <strong>the</strong> phylogenetic analyses, <strong>to</strong>pologically<br />
constraint MP and ML analyses were used <strong>to</strong> evaluate<br />
how many times hypogeous taxa have been derived from<br />
epigeous apo<strong>the</strong>cia-forming taxa, with loss of forcible spore<br />
discharge. Constraint <strong>to</strong>pologies were manually specified in<br />
PAUP. The MP analyses were performed under <strong>the</strong> constraints,<br />
using <strong>the</strong> same settings as specified above (Hansen et al. 2005).<br />
The ML analyses consisted of heuristic searches with ten random<br />
addition sequence replicates, tree bisection–reconnection<br />
(TBR) branch swapping and starting trees obtained via<br />
stepwise addition. The ML GTR þ I þ G model parameters<br />
used, were fixed <strong>to</strong> values estimated from one of <strong>the</strong> unconstrained<br />
MP trees (from <strong>the</strong> original MP analyses). The<br />
Kishino–Hasegawa test (Kishino & Hasegawa 1989) and <strong>the</strong><br />
Shimodiara–Hasegawa tests (Shimodaira & Hasegawa 1999)<br />
were used <strong>to</strong> compare constrained and unconstrained <strong>to</strong>pologies<br />
in PAUP version 4.0b10.<br />
Results<br />
Phylogenetic relationships of truffles within lineage A<br />
The LSU dataset of lineage A included 973 characters with 338<br />
being parsimony informative. Parsimony analyses resulted in<br />
1391 equally MPTs (1327 steps, CI ¼ 0.333, RI ¼ 0.678). The<br />
Pezizaceae are highly supported as monophyletic (PB 99 %, PP<br />
100 %), with Ascobolaceae as <strong>the</strong> sister group (PB 97 %, PP 100,<br />
Fig 2). The strict consensus tree of all MPTs is highly resolved,<br />
but <strong>the</strong> deep level relationships are not well supported. Fourteen<br />
fine-scale lineages that correspond <strong>to</strong> <strong>the</strong> lineages resolved<br />
in Hansen et al. (2005) are recovered by all analyses.<br />
The 17 truffle species (11 genera) sampled are nested within<br />
five or six of <strong>the</strong> 14 lineages; Eremiomyces echinulatus is resolved<br />
separately with Peziza vacini in <strong>the</strong> MP analysis (Fig 2),<br />
but is placed in <strong>the</strong> Plicaria–Hapsidomyces lineage, along with<br />
Peziza phyllogena in ML and Bayesian analyses. The truffle<br />
Amylacus tasmanicus forms a highly supported sister taxon<br />
(PB/PP 100 %), <strong>to</strong> a highly supported clade of three species of<br />
<strong>the</strong> truffle genus Pachyphloeus, <strong>the</strong> anamorph Glischroderma<br />
sp. and <strong>the</strong> apo<strong>the</strong>cial Scabropezia (PB 98 %, PP 100 %). The<br />
two species of <strong>the</strong> truffle genus Hydnotryopsis form a strongly<br />
supported group with Sarcosphaera (PB/PP 100 %). The three<br />
specimens of Sarcosphaera coronaria (from North America and<br />
Denmark) exhibit quite large sequence variation, but form<br />
a monophyletic group (PP 95 %). The placement of Mattirolomyces<br />
is uncertain; it is deeply nested within <strong>the</strong> Peziza s. str. lineage<br />
in <strong>the</strong> strict consensus tree of all MP trees, but is grouping<br />
with Iodophanus, as a sister group <strong>to</strong> <strong>the</strong> Peziza s. str. lineage in<br />
ML and Bayesian analyses (none of <strong>the</strong>se positions are with
80<br />
Neolecta vitellina<br />
100 Byssonectria terrestris<br />
98 Melastiza con<strong>to</strong>rta<br />
Otidea onotica<br />
100 Otidea umbrina<br />
Smardaea amethystina<br />
100<br />
Greletia reticulosperma<br />
Morchella elata<br />
Ascobolus carbonarius<br />
100<br />
Ascobolus denudatus<br />
81 Ascobolus crenulatus<br />
Marcelleina pseudoanthracina<br />
76<br />
Marcelleina persoonii<br />
71<br />
Peziza gerardii (2)<br />
100 Peziza gerardii (1)<br />
Iodophanus hyperboreus<br />
Iodophanus carneus<br />
Amylascus tasmanicus<br />
100<br />
Scabropezia flavovirens<br />
89<br />
Scabropezia scabrosa<br />
Pachyphloeus melanoxanthus<br />
Glischroderma sp.<br />
Pachyphloeus citrinus (1)<br />
98<br />
Pachyphloeus citrinus (2)<br />
Pachyphloeus virescens<br />
100<br />
77<br />
100<br />
Peziza natrophila<br />
Peziza quelepidotia<br />
Peziza apiculata<br />
Boudiera tracheia<br />
Boudiera dennisii<br />
Pachyella babing<strong>to</strong>nii<br />
Pachyella punctispora<br />
Pachyella violaceonigra<br />
Pachyella habrospora<br />
Peziza succosa<br />
Peziza succosella<br />
Peziza michelii<br />
Peziza sp.<br />
Pezizaceae<br />
Sarcosphaera coronaria (1)<br />
Sarcosphaera coronaria (2)<br />
Sarcosphaera coronaria (3)<br />
Hydnotryopsis sp.<br />
Hydnotryopsis setchellii<br />
Mattirolomyces terfezioides<br />
Peziza howsei<br />
Peziza proteana, petersii<br />
Peziza exogelatinosa<br />
Peziza proteana f. sparassioides<br />
Peziza lobulata<br />
Peziza subviolacea<br />
Peziza ampelina<br />
Peziza subcitrina<br />
Peziza echinispora<br />
Peziza varia<br />
Peziza arvernensis<br />
Peziza ampliata<br />
Peziza vesiculosa<br />
Iodowynnea auriformis (2)<br />
Iodowynnea auriformis (1)<br />
75 Kalaharituber pfeilii<br />
Peziza luteoloflavida<br />
Peziza obtusapiculata<br />
Peziza polaripapulata<br />
Peziza retrocurvata<br />
Ruhlandiella berolinensis<br />
Peziza whitei<br />
Peziza limnaea<br />
Peziza badia<br />
Peziza alaskana<br />
Peziza badiofusca<br />
Peziza saniosa<br />
Peziza depressa<br />
Peziza griseorosea<br />
Peziza atrovinosa<br />
Peziza ellipsospora<br />
Terfezia boudieri (1)<br />
Terfezia boudieri (2)<br />
Terfezia claveryi (1)<br />
Terfezia claveryi (2)<br />
Cazia flexiascus<br />
Tirmania pinoyi<br />
Tirmania nivea<br />
Peziza ostracoderma<br />
Peziza phyllogena (1, 2)<br />
Hapsidomyces venezuelensis<br />
Plicaria carbonaria<br />
Plicaria trachycarpa<br />
Plicaria endocarpoides<br />
Peziza vacini<br />
Eremiomyces echinulatus<br />
Peziza bananicola<br />
Peziza subisabellina (2)<br />
Peziza subisabellina (1)<br />
10 changes<br />
100<br />
100<br />
100<br />
78<br />
100<br />
100<br />
90<br />
92<br />
78<br />
93<br />
100/95<br />
91<br />
98/74<br />
94<br />
100<br />
100<br />
98<br />
100<br />
100<br />
100<br />
100<br />
100<br />
Pachyphloeus-<br />
Amylascus<br />
100<br />
100<br />
100/89<br />
100 98<br />
100/99<br />
100<br />
97<br />
100<br />
100<br />
100<br />
100<br />
98<br />
100<br />
100<br />
99<br />
95<br />
* 95<br />
Sarcosphaera-<br />
100<br />
Hydnotryopsis<br />
*<br />
96<br />
Peziza s. str.<br />
96/72<br />
*<br />
98<br />
97<br />
100<br />
*<br />
Iodowynnea-Kaliharituber<br />
*<br />
100<br />
100<br />
99/76<br />
*<br />
*<br />
97/<br />
* *<br />
Peziza depressa-Ruhlandiella<br />
100<br />
100<br />
100<br />
100/94<br />
100/98<br />
infolded or chambered<br />
*<br />
ptyco<strong>the</strong>cium<br />
*<br />
solid ptyco<strong>the</strong>cium<br />
stereo<strong>the</strong>cia<br />
exo<strong>the</strong>cium<br />
100<br />
99<br />
100/98<br />
Fig 2 – Phylogenetic relationships among epigeous and hypogeous taxa in Pezizaceae (lineage A), derived from parsimony<br />
analyses of LSU rDNA sequences. One of 1391 most parsimonious trees. Terminal taxa represent individual specimens<br />
(from Hansen et al. 2001, 2005; Ferdman et al. 2005; Norman & Egger 1999). Neolecta vitellina was used <strong>to</strong> root <strong>the</strong><br />
phylogeny. Hypogeous lineages are shown in bold. Numbers above branches represent PP ( 95 %). Numbers below<br />
branches represent PB support ( 70 %). Symbols by taxon names indicate specific fruiting body types of truffles.<br />
Fine-scale lineages, as defined in Hansen et al. (2005), that include truffles are indicated for discussion in <strong>the</strong> text.
1080 T. Læssøe, K. Hansen<br />
100<br />
100<br />
Peziza vesiculosa<br />
Peziza depressa<br />
Iodophanus carneus<br />
100 Morchella conica<br />
100 Morchella esculenta<br />
Verpa bohemica<br />
Verpa conica<br />
Disciotis venosa<br />
Fischerula subcaulis<br />
Morchellaceae<br />
100<br />
Leucangium carthusianum<br />
98 Pseudorhizina californica<br />
Discina macrospora<br />
Gyromitra melaleucoides<br />
Hydnotrya cerebriformis<br />
Discinaceae<br />
99/73 Hydnotrya cubispora<br />
Balsamia magnata<br />
91 Barssia oregonensis<br />
Underwoodia columnaris<br />
Wynnella silvicola<br />
Helvella crispa<br />
93<br />
96<br />
Helvella rivularis<br />
Helvella pezizoides<br />
Helvella aff. cupuliformis<br />
Helvella albella<br />
Helvella atra<br />
Helvella lacunosa<br />
98/78 Tuber californicum<br />
Tuber puberulum (1)<br />
Tuber puberulum (2)<br />
90 Tuber oligospermum<br />
77 Tuber borchii<br />
Tuber maculatum<br />
Tuber canaliculatum<br />
100 99<br />
Tuber gibbosum<br />
Tuber aff. gibbosum<br />
Tuber rufum var. rufum<br />
Tuber melanosporum<br />
100<br />
84<br />
95<br />
Tuber excavatum<br />
Dingleya verrucosa<br />
Reddellomyces donkii<br />
Labyrinthomyces varius<br />
Choiromyces venosus<br />
Choiromyces alveolatus<br />
Rhizina undulata<br />
Caloscypha fulgens<br />
100/97<br />
100<br />
100<br />
100<br />
*<br />
*<br />
*<br />
100/89<br />
98<br />
100<br />
100<br />
100/70<br />
Rhizinaceae<br />
Caloscyphaceae<br />
significant support). Kaliharituber is suggested as closely related<br />
<strong>to</strong> Iodowynnea (PB 75 %). The truffle genera Cazia, Ruhlandiella,<br />
Terfezia, and Tirmania, and two truffle species of Peziza,<br />
P. ellipsospora and P. whitei, are resolved among apo<strong>the</strong>ciaforming<br />
Peziza species in <strong>the</strong> P. depressa–Ruhlandiella lineage.<br />
This lineage, excluding Ruhlandiella, is supported by 100 %<br />
PP, but is with only 53 % PB.<br />
At least nine independent origins of hypogeous forms are<br />
supported by <strong>the</strong> LSU gene trees (Fig 2). Constrained MP and<br />
ML analyses forcing <strong>the</strong> two species of Hydnotryopsis <strong>to</strong> be<br />
monophyletic could not be rejected (Table 1). Likewise, forced<br />
monophyly of <strong>the</strong> hypogeous taxa within <strong>the</strong> P. depressa–<br />
Ruhlandiella lineage (not including Eremiomyces), did not yield<br />
trees that were significantly longer than <strong>the</strong> unconstrained<br />
MP trees. However, under this constraint <strong>the</strong> ML tree was<br />
significantly worse than <strong>the</strong> unconstrained optimal ML tree<br />
(Table 1). Trees rejected by MP and ML include <strong>the</strong> following<br />
monophyly constraints: truffles in <strong>the</strong> P. depressa lineage<br />
Helvellaceae<br />
Tuberaceae<br />
infolded or chambered<br />
ptyco<strong>the</strong>cium<br />
solid ptyco<strong>the</strong>cium<br />
stereo<strong>the</strong>cia<br />
10 changes<br />
Fig 3 – Phylogenetic relationships among epigeous and hypogeous taxa within <strong>the</strong> families Morchellaceae, Discinaceae,<br />
Helvellaceae and Tuberaceae (lineage B), derived from parsimony analyses of LSU rDNA sequences. One of three most<br />
parsimonious trees. Terminal taxa represent individual specimens (primarily from O’Donnell et al. 1997). Peziza vesiculosa,<br />
P. depressa and Iodophanus carneus were used <strong>to</strong> root <strong>the</strong> phylogeny. Hypogeous lineages are shown in bold. Numbers<br />
above branches represent PP ( 95 %). Numbers below branches represent PB support ( 70 %). Symbols by taxon names<br />
indicate specific fruiting body types of truffles.<br />
including Eremiomyces (with or without Ruhlandiella), Amylascus–Pachyphloeus,<br />
Pachyphloeus, Mattirolomyces with Terfezia,<br />
and Kaliharituber with Terfezia (Table 1). The most conservative<br />
conclusion is thus, that forcible spore discharge has been<br />
lost only once within each of <strong>the</strong> lineages Sarcosphaera–<br />
Hydnotryopsis and P. depressa–Ruhlandiella, once in Eremiomyces,<br />
Kaliharituber, Mattirolomyces, and Amylascus, and three times in<br />
Pachyphloeus (assuming that active spore discharge, once lost,<br />
can not be regained).<br />
Phylogenetic relationships of truffles within lineage B<br />
Parsimony analyses of lineage B yielded three equally MPTs<br />
(1235 steps, CI ¼ 0.423, RI ¼ 0.639) produced from 699 characters,<br />
of which 233 were parsimony informative. The strict consensus<br />
tree of <strong>the</strong> three MPTs is highly resolved, but support<br />
for <strong>the</strong> families are lacking, except for Tuberaceae (PB 84 %,<br />
PP 100 %, Fig 3). The trees recovered by MP, Bayesian, and
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1081<br />
Pyronemataceae<br />
100<br />
100<br />
Ascobolus carbonarius<br />
Peziza vesiculosa<br />
100<br />
98<br />
Smardaea amethystina<br />
Greletia reticulosperma<br />
99<br />
100 Otidea onotica<br />
98 Otidea concinna<br />
Otidea alutacea<br />
Humaria hemisphaerica (1, 2)<br />
10 changes<br />
73<br />
100/ Genea hispidula (1)<br />
100<br />
100<br />
Genea hispidula (2)<br />
100<br />
Genea sp.<br />
100 Genea harknessii (1)<br />
100/83<br />
100 Genea harknessii (2)<br />
99/86 Genea arenaria<br />
Genea verrucosa<br />
Parascutellinia carneosanguinea<br />
Wilcoxina mikolae<br />
100/81 Wilcoxina rehmii<br />
Pyronema confluens<br />
Melastiza cornubiensis<br />
Aleuria aurantia<br />
Byssonectria terrestris<br />
Cheilymenia vitellina<br />
100/<br />
100 Geopora cooperi<br />
96/74 99 Geopora cooperi f. gilkeyae<br />
100 Geopora sp. 2<br />
100 Geopora sp. 3<br />
99 Geopora cf. cervina<br />
100 96/ Geopora sp. 1<br />
100/98 Geopora arenicola (1, 2)<br />
96 Miladina lecithina<br />
100<br />
Ramsbot<strong>to</strong>mia asperior<br />
Scutellinia scutellata<br />
Trichophaea woolhopeia<br />
Sphaerosporella brunnea<br />
Anthracobia macrocystis<br />
Sowerbyella imperialis<br />
100 Tarzetta pusilla<br />
99<br />
100 Tarzetta catinus<br />
Stephensia shanorii<br />
Stephensia bombycina<br />
98 74 Geopyxis carbonaria (1, 2)<br />
Paurocotylis pila<br />
Geopyxis sp.<br />
Lasiobolus cuniculi<br />
100 Lasiobolus ciliatus<br />
92 Ascodesmis nigricans<br />
100 Eleu<strong>the</strong>rascus lectardii<br />
Pulvinula constellatio<br />
100 Pulvinula convexella<br />
Pseudombrophila merdaria<br />
100/100 Pseudombrophila <strong>the</strong>ioleuca<br />
Oc<strong>to</strong>spora axillaris<br />
76<br />
96<br />
100<br />
Neottiella rutilans<br />
Lamprospora cf. ascoboloides<br />
Lamprospora dictydiola<br />
100<br />
ptyco<strong>the</strong>cia, infolded or<br />
chambered<br />
ascoma without hymenium,<br />
chambered<br />
100/<br />
100<br />
*<br />
100/<br />
*<br />
*<br />
100<br />
100<br />
100<br />
100<br />
100<br />
100<br />
100<br />
Ascodesmidaceae<br />
100<br />
100<br />
Fig 4 – Phylogenetic relationships among epigeous and hypogeous taxa in Pyronemataceae (lineage C), derived from<br />
parsimony analyses of LSU rDNA data consisting of 894 aligned nucleotides for 56 taxa. One of three most parsimonious<br />
trees. Terminal taxa represent individual specimens. Hypogeous lineages are shown in bold. Numbers above branches<br />
represent PP ( 95 %). Numbers below branches represent PB support ( 70 %). Symbols by taxon names indicate specific<br />
fruiting body types of truffles.<br />
ML analyses did not possess any supported conflict. Bayesian<br />
analyses support Helvellaceae (PP 99 %) excluding Underwoodia<br />
columnaris, which is unresolved. A Morchellaceae–Discinaceae<br />
(PP 100 %) and a Helvellaceae–Tuberaceae lineage are resolved<br />
by MP and ML analyses (Fig 3), in accordance with O’Donnell<br />
et al. (1997), who used both SSU and LSU. The truffles Leucangium<br />
and Fischerula subcaulis are variously placed within <strong>the</strong><br />
Morchellaceae–Discinaceae lineage, and <strong>the</strong>ir exact position is<br />
unknown. Two species of Hydnotrya, H. cerebriformis and<br />
H. cubispora, form a monophyletic group (PB 73 %, PP 99 %)<br />
nested within <strong>the</strong> Discinaceae in all analyses. Balsamia, B. magnata<br />
and B. oregonensis, is likewise monophyletic (PB 91 %, PP<br />
100 %) and forms a sister group <strong>to</strong> a highly supported clade<br />
of apo<strong>the</strong>cial Helvella species and Wynella silvicola in all analyses.<br />
The 11 species of Tuber included form a monophyletic<br />
group (PB 69 %, PP 100 %), as a sister group <strong>to</strong> a clade of four<br />
additional truffle genera, Dingleya, Reddellomyces, Labyrinthomyces,<br />
and Choiromyces s. str.<br />
The most parsimonious interpretation of <strong>the</strong> LSU phylogeny<br />
suggests that <strong>the</strong> truffle form originated four times<br />
within lineage B (Fig 3). Never<strong>the</strong>less, constraint MP and ML<br />
analyses forcing Fischerula, Leucangium, and Hydnotrya in<strong>to</strong> a<br />
monophyletic group could not be rejected (Table 1). This suggests<br />
that forcible spore discharge has been lost at least three<br />
times within lineage B, once in <strong>the</strong> Morchellaceae–Discinaceae<br />
lineage, once in Helvellaceae, and in Tuberaceae.<br />
Phylogenetic relationships of truffles within lineage C<br />
Parsimony analyses of lineage C yielded three equally MPTs<br />
(1679 steps, CI ¼ 0.424, RI ¼ 0.637) from 894 <strong>to</strong>tal characters,<br />
of which 302 were parsimony informative. The strict
1082 T. Læssøe, K. Hansen<br />
Table 1 – Evaluation of different constrained tree <strong>to</strong>pologies in MP and ML analyses, compared with <strong>the</strong> MPTs and <strong>the</strong><br />
optimal MLT, respectively, using <strong>the</strong> Kishino–Hasegawa test for MP and <strong>the</strong> Shimodiara–Hasegawa test for ML ( p < 0.05)<br />
Tree MP ML<br />
Tree lenght a<br />
consensus tree of <strong>the</strong> three MPTs is nearly completely resolved,<br />
but as for <strong>the</strong> lineages A and B <strong>the</strong> deep level relationships<br />
are poorly supported. Pyronemataceae are suggested <strong>to</strong> be<br />
paraphyletic, because Ascodesmidaceae are nested within it.<br />
Ascodesmidaceae are highly supported as monophyletic<br />
(Fig 4). Twelve clades of pyronemataceous taxa are recovered<br />
by all analyses, which correspond <strong>to</strong> those identified by Perry<br />
et al. (2007) who used a much larger taxon sampling. The nine<br />
truffle species included are nested within three, moderate <strong>to</strong><br />
highly supported clades with apo<strong>the</strong>cial pyronemataceous<br />
taxa (Fig 4). The five species of <strong>the</strong> hypogeous genus Genea<br />
form a monophyletic group (PB 86 %, PP 99 %), as a sister group<br />
<strong>to</strong> <strong>the</strong> epigeous Humaria hemisphaerica (PB/PP 100 %). The truffle<br />
Geopora cooperi, forms a highly supported monophyletic<br />
group with five epigeous species of Geopora (PB/PP 100 %).<br />
Geopora is suggested <strong>to</strong> be a sister group <strong>to</strong> a clade of <strong>the</strong><br />
apo<strong>the</strong>cial Ramsbot<strong>to</strong>mia, Scutellinia, and Miladina (PP 100 %).<br />
The truffles Stephensia and Paurocotylis pila form a highly supported<br />
group with apo<strong>the</strong>cial Tarzetta and Geopyxis (PB 99 %, PP<br />
100 %). Stephensia is suggested <strong>to</strong> be non-monophyletic;<br />
Stephensia bombycina form a well-supported group with<br />
Geopyxis carbonaria (PB 74 %, PP 100 %), with Paurocotylis pila<br />
(PP 98 %), Geopyxis sp. (PP 100 %), and Stephensia shanorii as successive<br />
sister taxa.<br />
The most parsimonious interpretation of <strong>the</strong> LSU phylogeny<br />
suggests that forcible spore discharge has been lost at<br />
least five times within <strong>the</strong> Pyronemataceae (in Genea, Geopora<br />
cooperi (not completely), Paurocotylis and twice in Stephensia).<br />
The constraint analyses forcing Stephensia <strong>to</strong> be monophyletic,<br />
or Stephensia and Paurocotylis <strong>to</strong> be monophyletic were rejected<br />
(Table 1).<br />
Significantly<br />
worse?<br />
Evolution of ascomata types<br />
At least five different forms of ascomata exist within Pezizales.<br />
Epigeous apo<strong>the</strong>cia of various shapes with forcible spore discharge<br />
are <strong>the</strong> most common form and occur in each of <strong>the</strong><br />
A, B, and C lineages. This is likely <strong>the</strong> ancestral form, and<br />
<strong>the</strong> molecular data suggest that <strong>the</strong> apo<strong>the</strong>cia-forming<br />
Pezizales have given rise <strong>to</strong> at least four different types of<br />
hypogeous ascomata without forcible spore discharge ( pro<br />
parte sensu Weber et al. 1997): ptycho<strong>the</strong>cia [hollow <strong>to</strong> folded<br />
with internal hymenia, in Pezizaceae, Discinaceae, Helvellaceae,<br />
Tuberaceae and Pyronemataceae (Figs 2–4)]; stereo<strong>the</strong>cia [solid<br />
without hymenia, in Pezizaceae, Discinaceae–Morchellaceae,<br />
and Tuberaceae (Figs 2 and 3)]; exo<strong>the</strong>cia [external hymenia,<br />
Ruhlandiella (Pezizaceae, Fig 2)]; and an unnamed type found<br />
in Glaziella and Paurocotylis (Glaziellaceae and Pyronemataceae,<br />
Fig 4; recalls bladder-shaped ptycho<strong>the</strong>cia, but without organized<br />
hymenia). The molecular data suggests that ptycho<strong>the</strong>cia<br />
and stereo<strong>the</strong>cia have evolved multiple times in different<br />
lineages within Pezizales.<br />
Taxonomy<br />
Ln likelihood Difference<br />
in LnL<br />
P-value Significantly<br />
worse?<br />
Lineage A, unconstrained MPT 2078 Best – – – –<br />
Lineage A, unconstrained optimal MLT – – 11183.03738 – – Best<br />
Hydnotryopsis monophyletic 2082 (þ4) No 11189.40900 6.37162 0.083 No<br />
<strong>Truffle</strong>s in ‘P. depressa lineage’ monophyletic<br />
(including Ruhlandiella and Eremiomyces)<br />
2095 (þ17) Yes 11224.21753 41.18015 0.006* Yes<br />
<strong>Truffle</strong>s in ‘P. depressa lineage’ monophyletic<br />
(not including Ruhlandiella,<br />
but including Eremiomyces)<br />
2093 (þ15) Yes 11213.75681 30.71942 0.004* Yes<br />
<strong>Truffle</strong>s in ‘P. depressa lineage’ monophyletic<br />
(not including Eremiomyces,<br />
but including Ruhlandiella)<br />
2085 (þ7) No 11201.55494 18.51755 0.020* Yes<br />
Amylascus and Pachyphloeus monophyletic 2098 (þ16) Yes 11219.85875 36.82137 0.041* Yes<br />
Pachyphloeus monophyletic 2090 (þ12) Yes 11214.23004 31.19266 0.005* Yes<br />
Mattirolomyces with Terfezia 2094 (þ12) Yes 11215.54524 32.50785 0.009* Yes<br />
Kaliharituber with Terfezia 2098 (þ20) Yes 11218.85867 35.82129 0.051 No<br />
Lineage B, unconstrained MPT 1235 Best – – – –<br />
Lineage B, unconstrained optimal MLT – – 6540.88728 – – Best<br />
Fischerula–Leucangium with Hydnotrya 1239 (þ4) No 6550.10480 9.21752 0.077 No<br />
Lineage C, unconstrained MPT 1679 Best – – – –<br />
Lineage C, unconstrained MLT – – 8958.87503 – – Best<br />
Stephensia with Paurocotylis 1694 (þ15) Yes 8991.20102 32.32599 0.001* Yes<br />
Stephensia monophyletic 1692 (þ13) Yes 8992.05211 33.17708 0.001* Yes<br />
a Difference in length between MPTs and constrained trees in paren<strong>the</strong>ses.<br />
Taxonomic implications: an overview of accepted<br />
hypogeous Pezizales taxa<br />
Lineage A<br />
The Ascobolaceae have no confirmed hypogeous representatives<br />
but various truffle taxa have at times been placed in
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1083<br />
<strong>the</strong> family, e.g. Sphaerosoma and Ruhlandiella (as Muciturbo) (e.g.<br />
Castellano et al. 2004). See Figs 2 and 5A-D.<br />
Pezizaceae Dumort. 1829 (syn. Terfeziaceae E. Fisch. 1897)<br />
The family Terfeziaceae as defined by Zhang (1992a, 1992b)<br />
are included in this family, but was accepted in <strong>the</strong> latest<br />
Dictionary of <strong>the</strong> Fungi (Kirk et al. 2001). Recent molecular results<br />
(e.g. Norman & Egger 1999; Hansen et al. 2005) clearly demonstrate<br />
it should be relegated <strong>to</strong> synonymy of <strong>the</strong> Pezizaceae (see<br />
review in Hansen & Trappe 2002). Thirteen out of 25 genera in<br />
<strong>the</strong> Pezizaceae (Eriksson 2006a) are exclusively truffle or trufflelike<br />
taxa, but several truffle species have also been described<br />
in Peziza. Hansen et al. (2001) gave a review of <strong>the</strong> genera.<br />
The genus Peziza was found <strong>to</strong> be non-monophyletic and all<br />
o<strong>the</strong>r pezizaceous genera nested within it (Hansen et al.<br />
2001, 2005), and a revised generic arrangement is under way<br />
(Hansen & Pfister, in preparation.). Two lineages discovered<br />
comprise most of <strong>the</strong> Peziza species, <strong>the</strong> Peziza s. str. and <strong>the</strong><br />
P. depressa–Ruhlandiella lineages, <strong>the</strong> latter including several<br />
truffles (Cazia, Peziza ellipsospora, P. whitei, Ruhlandiella, Terfezia<br />
and Tirmania; Fig 2). The P. depressa–Ruhlandiella lineage was<br />
highly supported in combined analyses of LSU, b-tubulin,<br />
and RPB2 (Hansen et al. 2005). Only one truffle genus, Mattirolomyces,<br />
clusters in Peziza s. str. in MP analyses, but without<br />
support (Fig 2). Three types of hypogeous ascomata exist<br />
within <strong>the</strong> family (Fig 2). The Amylascus–Pachyphloeus and<br />
<strong>the</strong> P. depressa–Ruhlandiella lineages produce both ptycho<strong>the</strong>cia<br />
and stereo<strong>the</strong>cia. The cardinal feature of Pezizaceae, <strong>the</strong><br />
amyloid reaction of <strong>the</strong> ascus wall, has been lost in several<br />
of <strong>the</strong> hypogeous taxa (e.g. Cazia and Terfezia).<br />
Amylascus Trappe 1971<br />
Type: Amylacus herbertianus.<br />
The type species of Amylacus has not been sampled for molecular<br />
phylogenetic study, but <strong>the</strong> genus is most likely monophyletic<br />
[A. tasmanicus has even been considered a synonym<br />
of A. herbertianus (Bea<strong>to</strong>n & Weste 1982)] and is suggested <strong>to</strong><br />
be closely related <strong>to</strong> Scabropezia and Pachyphloeus. Amylascus<br />
was originally placed in <strong>the</strong> Terfeziaceae or Geneaceae (Trappe<br />
1971, 1975a), but later, based on <strong>the</strong> thick-walled, amyloid<br />
asci, was placed in <strong>the</strong> Pezizaceae (Trappe 1979). Trappe<br />
(1975a) and Bea<strong>to</strong>n & Weste (1982) monographed <strong>the</strong> genus.<br />
Amylascus includes only <strong>the</strong> two mentioned species, both<br />
recorded only in Australia.<br />
Cazia Trappe 1989<br />
Type: Cazia flexiascus.<br />
Originally, and at times by some subsequent authors,<br />
placed in <strong>the</strong> Helvellaceae (Trappe 1989), but Kirk et al. (2001)<br />
place it in <strong>the</strong> Terfeziaceae. O’Donnell et al. (1997) were <strong>the</strong> first<br />
<strong>to</strong> place Cazia in <strong>the</strong> Pezizaceae. As can be seen from Fig 2, itis<br />
nested within <strong>the</strong> P. depressa–Ruhlandiella lineage containing<br />
both epigeous and hypogeous taxa. Cazia quercicola Fogel &<br />
States (2002) is only <strong>the</strong> second recognized species.<br />
Eremiomyces Trappe & Kagan-Zur 2005<br />
Type: Eremiomyces echinulatus (syn. Choiromyces echinulatus).<br />
Ferdman et al. (2005) found this species <strong>to</strong> cluster within <strong>the</strong><br />
Pezizaceae (with Terfezia and Tirmania species) and not with <strong>the</strong><br />
type of Choiromyces, which has affinities with <strong>the</strong> Tuberaceae.<br />
Fig 5 – Fruiting body forms in lineage A (Pezizaceae). (A-B) Sarcosphaera coronaria (A) Closed apo<strong>the</strong>cia, JHP-95.074 (C). (B) Open<br />
apo<strong>the</strong>cia. (C) Hydnobolites cerebriformis, ptycho<strong>the</strong>cia. (D) Terfezia lep<strong>to</strong>derma, stereo<strong>the</strong>cia. Pho<strong>to</strong>s: J.H. Petersen (A),<br />
K. Hansen (B), J. Nitare (C), J. San<strong>to</strong>s (D).
1084 T. Læssøe, K. Hansen<br />
Besides <strong>the</strong> molecular results <strong>the</strong> highly inflated exipular cells<br />
also suggest this fungus belongs <strong>to</strong> Pezizaceae ra<strong>the</strong>r than<br />
Tuberaceae. The exact placement of Eremiomyces within Pezizaceae<br />
is not resolved in our analyses, but it is likely among members<br />
of <strong>the</strong> P. depressa–Ruhlandiella, Plicaria–Hapsidomyces or P.<br />
phyllogena lineages (<strong>the</strong> inclusive clade A in Hansen et al. 2005).<br />
Hydnobolites Tul. & C. Tul. 1843 (Fig 5C)<br />
Type: Hydnobolites cerebriformis.<br />
This genus apparently has only two accepted species,<br />
H. cerebriformis from Europe and H. californicus from North<br />
America. The type species has saccate, amyloid [when pretreated<br />
in potassium hydroxide (KOH)] asci formed in poorly<br />
defined hymenia, without well-differentiated paraphyses, in<br />
brain-like, pale ascomata. The spores are globose with a reticulate<br />
and spinulose ornament. The genus was previously placed<br />
in <strong>the</strong> Tuberaceae (Gilkey 1955; Korf 1973a; Castellano et al. 2004)<br />
or in <strong>the</strong> Terfeziaceae (Hawker 1954; Trappe 1971, 1979). Trappe<br />
(1979) regarded Hydnobolites <strong>to</strong> be close <strong>to</strong> Pachyphloeus and<br />
Terfezia (Fig 5D). Kimbrough et al. (1991) suggested a placement<br />
in <strong>the</strong> Pezizaceae based on ultrastructural observations of septal<br />
pores. They also found <strong>the</strong> asci <strong>to</strong> be weakly amyloid after treatment<br />
in 2 % KOH. No molecular data are available for Hydnobolites,<br />
and <strong>the</strong> placement is mainly based on <strong>the</strong> amyloid asci and<br />
<strong>the</strong> suggested close relationship <strong>to</strong> Pachyphloeus and Terfezia.<br />
Hydnotryopsis Gilkey 1916<br />
Type: Hydnotryopsis setchellii.<br />
Gilkey (1954) later abandoned <strong>the</strong> genus and placed it in<br />
Choiromyces. In agreement with Hansen et al. (2005), Hydnotryopsis<br />
setchelli and an unnamed Hydnotryopsis are suggested<br />
as closely related <strong>to</strong> <strong>the</strong> near hypogeous Sarcosphaera coronaria<br />
(Figs 2 and 5A-B). The constraint analyses forcing <strong>the</strong> two Hydnotryopsis<br />
species <strong>to</strong> be monopyletic could not be rejected<br />
(Table 1). Hydnotryopsis was placed in <strong>the</strong> Pezizaceae by Fischer<br />
(1938), and based on <strong>the</strong> diffusely amyloid asci, followed by<br />
e.g. Trappe (1975c, 1979). The solid ascomata have a peridium<br />
of globose cells, and asci and paraphyses in a hymenial<br />
configuration.<br />
Kalaharituber Trappe & Kagan-Zur 2005<br />
Type: Kalaharituber pfeilii (syn. Terfezia pfeilii).<br />
Ferdman et al. (2005) demonstrated (using ITS and LSU) <strong>the</strong><br />
non-monophyletic nature of Terfezia and erected Kalaharituber<br />
for a sou<strong>the</strong>rn African desert truffle originally described as<br />
T. pfeilii (basionym in error given as Tuber pfeilii). No epigeous<br />
representatives were included in <strong>the</strong>ir analyses. Our analyses<br />
indicate a relationship with <strong>the</strong> epigeous Iodowynnea (PB 75 %,<br />
Fig 2). Taylor et al. (1995) discussed <strong>the</strong> biology of K. pfeilii and<br />
suggested it could be mycorrhizal with species of Acacia, although<br />
a strong association with grasses was noted.<br />
Mattirolomyces E. Fisch. 1938<br />
Type: Choiromyces terfezioides (syn. Mattirolomyces terfezioides,<br />
Terfezia terfezioides).<br />
This genus was reinstated by Percudani et al. (1999) and accepted<br />
as such by Diéz et al. (2002) and Ferdman et al. (2005), after<br />
having been sunk under Terfezia, where it still recides in e.g.<br />
Montecchi & Sarasini (2000). Unlike species of Terfezia, M. terfezioides<br />
occurs in woodland or in ruderal habitats ra<strong>the</strong>r than in<br />
deserts (e.g. Montecchi & Sarasini 2000). Kovács et al. (2003)<br />
reviewed <strong>the</strong> mycorrhizae studies on Mattirolomyces and similar<br />
taxa and concluded that <strong>the</strong>re is no clear evidence for a mycorrhizal<br />
function, and an ec<strong>to</strong>mycorrhizal ana<strong>to</strong>my does not<br />
develop (with Robinia or Helian<strong>the</strong>mum ovatum) but, instead, an<br />
ana<strong>to</strong>my referred <strong>to</strong> as ‘terfezioid’. Kovács et al. (2007) maintained<br />
that <strong>the</strong> trophic strategy of this fungus remains ambiguous.<br />
It forms sclerotia in <strong>the</strong> same manner as certain species<br />
of Morchella. Although <strong>the</strong> position of Mattirolomyces is uncertain<br />
in our analyses, constraint analyses forcing Mattirolomyces<br />
<strong>to</strong> group with Terfezia were rejected (Table 1). Healy (2003) described<br />
an additional American species, but based on molecular<br />
data (R. Healy, K. Hansen and G. Kovács, unpublished<br />
results) this species is not a member of Mattirolomyces.<br />
Mycoclelandia Trappe & Bea<strong>to</strong>n 1984 (syn. Clelandia)<br />
Type: Clelandia arenacea (syn. M. arenacea).<br />
Bea<strong>to</strong>n & Weste (1982) revised <strong>the</strong> two known species (as<br />
Clelandia) and Trappe & Bea<strong>to</strong>n (1984) replaced <strong>the</strong> invalid<br />
homonym Clelandia for Mycoclelandia. The asci stain strongly<br />
or diffused blue in iodine solutions. There are no sequences<br />
available, but based on <strong>the</strong> known morphological features<br />
<strong>the</strong> genus clearly belongs in <strong>the</strong> Pezizaceae.<br />
Pachyphloeus Tul & C. Tul. 1844 (syn. Pachyphlodes, Cryptica)<br />
Type: Pachyphloeus melanoxanthus.<br />
The ascomata typically have an apical depression or pore<br />
connecting <strong>to</strong> a few open veins. The peridium is verrucose<br />
and contains globose cells. Trappe (1979) placed <strong>the</strong> genus in<br />
<strong>the</strong> Terfeziaceae and gave <strong>the</strong> above synonymy (Trappe<br />
1975c). It had mainly been treated within <strong>the</strong> Tuberaceae (e.g.<br />
Knapp 1951; Korf 1973a). Amyloid asci occur in some species<br />
of Pachyphloeus (e.g. <strong>the</strong> type species), and based on this and<br />
ana<strong>to</strong>mical features <strong>the</strong> genus was placed in <strong>the</strong> Pezizaceae<br />
(Dissing & Korf 1980). This has been confirmed by molecular<br />
data (Norman & Egger 1999; Percudani et al. 1999; Hansen<br />
et al. 2005). Phylogenetic analyses of LSU suggest that <strong>the</strong><br />
type species is more closely related <strong>to</strong> species of Scabropezia<br />
than <strong>to</strong> o<strong>the</strong>r species of Pachyphloeus (PB 89 %, PP 100 %, Fig 2).<br />
Also, constraint analyses forcing <strong>the</strong> three included Pachyphloeus<br />
spp. <strong>to</strong> be monophyletic were rejected (Table 1). This<br />
suggests that Scabropezia may be a synonym of Pachyphloeus.<br />
Peziza Fr. 1822 (syn. Hydnoplicata)<br />
Type (lec<strong>to</strong>type): Peziza vesiculosa.<br />
Several hypogeous species, with passive spore dispersal,<br />
have been accepted in <strong>the</strong> o<strong>the</strong>rwise epigeous, apo<strong>the</strong>cial<br />
genus Peziza. Trappe (1979) noted six hypogeous species in<br />
Peziza and recently Peziza infossa (syn. P. quercicola) was added<br />
(Fogel & States 2002, 2003). Although this latter species is described<br />
as having operculate asci, no active spore discharge<br />
had been observed. Peziza has been demonstrated several<br />
times, using molecular phylogenetics, <strong>to</strong> be non-monophyletic<br />
(see above under Pezizaceae). The two pezizas with passive<br />
spore dispersal, P. whitei and P. ellipsospora, included in<br />
<strong>the</strong> molecular analyses, are nested within <strong>the</strong> P. depressa–Ruhlandiella<br />
lineage (Hansen et al. 2001, 2005)(Fig 2). In this lineage,<br />
<strong>the</strong>se two taxa represent a less derived truffle form; both<br />
produce infolded ptyco<strong>the</strong>cia, with a single opening, cylindrical<br />
asci with eight ascospores in a single row and paraphyses
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1085<br />
placed in hymenia. Both species have retained <strong>the</strong> amyloid reaction<br />
of <strong>the</strong> asci. More derived truffle forms in this lineage<br />
(Terfezia and Tirmania) produce compact ascomata (stereo<strong>the</strong>cia),<br />
with elongate-clavate <strong>to</strong> sub-globose asci (5-8 spored),<br />
randomly arranged in fertile areas, separated by sterile veins.<br />
Tirmania has amyloid asci, whereas this reaction is lost in<br />
Terfezia. The relationships among <strong>the</strong> taxa in <strong>the</strong> P. depressa–<br />
Ruhlandiella lineage are not unambiguously resolved, and a hypo<strong>the</strong>sis<br />
about <strong>the</strong> evolution of <strong>the</strong>se forms must await<br />
fur<strong>the</strong>r molecular studies using more variable gene regions<br />
and a larger taxon sampling. Trappe & Claridge (2006), never<strong>the</strong>less,<br />
resurrected Hydnoplicata for P. whitei based on <strong>the</strong> molecular<br />
results by Hansen et al. (2001). However, depending on<br />
<strong>the</strong> delineation within this lineage (see also Hansen et al. 2005<br />
and Fig 2), o<strong>the</strong>r possible and older generic names could be<br />
Terfezia or Tirmania. Hydnoplicata was based on H. whitei later<br />
transferred <strong>to</strong> Peziza (Trappe 1975c), and this was again<br />
confirmed by <strong>the</strong> molecular phylogenetic study by Hansen<br />
et al. (2001, 2005). Bea<strong>to</strong>n & Weste (1982) gave an account of<br />
P. whitei. Also Korf (1973b) discussed this species (as P. jactata).<br />
Ruhlandiella Henn. 1903 emend. Dissing & Korf 1980 (syn.<br />
Tremellodiscus C.G. Lloyd, ?Muciturbo P.H.B. Talbot 1989)<br />
Type: Ruhlandiella berolinensis.<br />
Ruhlandiella is more or less epigeous but with passive spore<br />
dispersal and with a some<strong>what</strong> convoluted ascoma, where <strong>the</strong><br />
hymenium covers <strong>the</strong> surface (exo<strong>the</strong>cial) ra<strong>the</strong>r than being<br />
disposed internally. The paraphyses have characteristic gelatinous<br />
sheaths. Dissing & Korf (1980) placed this genus in <strong>the</strong><br />
Pezizaceae with a proposed relationship <strong>to</strong> <strong>the</strong> genera Sphaerozone,<br />
Boudiera, and Plicaria. Molecular results place it in <strong>the</strong><br />
P. depressa–Ruhlandiella lineage (Hansen et al. 2005) (Fig 2).<br />
Muciturbo was accepted and listed in <strong>the</strong> Ascobolaceae by<br />
Castellano et al. (2004), but Galán & Moreno (1998) and Hansen<br />
(2000) suggest it as a synonym of Ruhlandiella based on a detailed<br />
comparative study of <strong>the</strong> proposed distinguishing characters.<br />
Dissing & Korf (1980) also noted that ano<strong>the</strong>r Hennings<br />
genus, Exogone, could represent an additional generic synonym<br />
and an additional species. Ruhlandiella (as Muciturbo)<br />
has been associated with a Chromelosporium anamorph<br />
(Warcup & Talbot 1989) in accordance with o<strong>the</strong>r connections<br />
in this clade (Hansen et al. 2005). Warcup & Talbot (1989)<br />
reported <strong>the</strong> spores of Muciturbo species <strong>to</strong> be uninucleate.<br />
Sphaerozone Zobel 1854 (syn. Sphaerosoma subgen. Tulasnia)<br />
Type: Sphaerozone ostiolatum (syn. S. tulasnei).<br />
This is a monotypic genus with exo<strong>the</strong>cial, more or less<br />
spherical, and <strong>to</strong> some extent convoluted ascomata, and<br />
amyloid asci. These characters, on current evidence place<br />
<strong>the</strong> genus within <strong>the</strong> Pezizaceae. The asci are more or less<br />
as in typical members of <strong>the</strong> family but indehiscent, and<br />
<strong>the</strong> paraphyses are likewise typical. The exposed hymenium<br />
also suggests a fairly recent radiation from actively dispersed<br />
ances<strong>to</strong>rs. Bea<strong>to</strong>n & Weste (1978) overlooked <strong>the</strong> amyloid asci<br />
in <strong>the</strong> type species. The non-amyloid species, Sphaerozone<br />
echinulatum and S. ellipsosporum, should not be accepted in<br />
<strong>the</strong> genus, as also stated in Bea<strong>to</strong>n & Weste (1982), and<br />
were duly transferred <strong>to</strong> Gymnohydnotrya (Zhang & Minter<br />
1989b). Dissing & Korf (1980) first noted <strong>the</strong> amyloidity of<br />
<strong>the</strong> asci in <strong>the</strong> type species and also clarified <strong>the</strong><br />
nomenclatural confusion surrounding <strong>the</strong> names Sphaerozone<br />
and Sphaerosoma. There is a certain resemblance <strong>to</strong> <strong>the</strong><br />
genus Ruhlandiella. All known collections are from <strong>the</strong><br />
vicinity of ec<strong>to</strong>trophic plants, so it is most likely ec<strong>to</strong>mycorrhizal.<br />
Montecchi & Sarasini (2000) illustrate and<br />
describe <strong>the</strong> genus but also cited Sphaerosoma as a synonym<br />
(see this).<br />
Terfezia (Tul. & C. Tul.) Tul. & C. Tul. 1851 (Fig 5D)<br />
Type (lec<strong>to</strong>type): Terfezia leonis (syn. Terfezia arenaria).<br />
Two species of Terfezia, T. boudieri and T. claveryi, are<br />
deeply nested within <strong>the</strong> P. depressa–Ruhlandiella lineage<br />
(Hansen et al. 2005) (Fig 2). The Terfeziaceae were based on<br />
<strong>the</strong> lack of structure in <strong>the</strong> arrangement of <strong>the</strong> asci that<br />
led early workers (e.g. Fischer 1897) <strong>to</strong> consider Terfezia outside<br />
<strong>the</strong> <strong>Tuberales</strong>. Vizzini (2003) considered <strong>the</strong> Tuberaceae<br />
and Terfeziaceae <strong>to</strong> exhibit extreme convergent morphology<br />
and also noted that <strong>the</strong> relationship of <strong>the</strong>se families have<br />
been especially controversial. Trappe (1971) accepted <strong>the</strong><br />
family Terfeziaceae within <strong>the</strong> <strong>Tuberales</strong> and later in <strong>the</strong><br />
Pezizales (Trappe 1979). Trappe & Sandberg (1977) studied<br />
<strong>the</strong> Japanese/North American non-desert species T. gigantea<br />
in detail and described a ra<strong>the</strong>r complicated ascospore wall<br />
with minute spines, while Janex-Favre & Parguey-Leduc<br />
(1985) and Janex-Favre et al. (1988) studied <strong>the</strong> ascus structure<br />
and ascospores in T. claveryi and T. lep<strong>to</strong>derma and found<br />
similarities <strong>to</strong> Tuber. Janex-Favre & Parguey-Leduc (2003)<br />
again studied <strong>the</strong> ascomata and concluded that Tuber and<br />
Terfezia should be retained within <strong>the</strong> <strong>Tuberales</strong>. Norman &<br />
Egger (1999) and Percudani et al. (1999) found evidence for<br />
apositionwithin<strong>the</strong>Pezizaceae (see also Kalaharituber and<br />
Mattirolomyces). Diéz et al. (2002), in a recent ITS study,<br />
hypo<strong>the</strong>sized a single origin of <strong>the</strong> so-called desert truffles,<br />
Tirmania and Terfezia, but included only hypogeous taxa<br />
and no o<strong>the</strong>r truffle taxa from <strong>the</strong> P. depressa–Ruhlandiella<br />
lineage. Trappe (1971) characterized <strong>the</strong> genus Terfezia as<br />
<strong>the</strong> most heterogenous genus in <strong>the</strong> Terfeziaceae. For a review<br />
of <strong>the</strong> mycorrhizal biology of <strong>the</strong> genus see Kovács et al.<br />
(2003).<br />
Tirmania Chatin 1892 [date disputed: 1890 sec Trappe; 1891<br />
sec Hansen et al. 2001]<br />
Type: Tirmania africana (syn. T. nivea).<br />
The amyloid reaction of <strong>the</strong> asci combined with a double<br />
ascospore wall, with <strong>the</strong> outer smooth and <strong>the</strong> inner with a reticulate-roughened<br />
wall, characterize <strong>the</strong> genus according <strong>to</strong><br />
Alsheikh & Trappe (1983a). The two species accepted by <strong>the</strong>se<br />
authors associate with species of Helian<strong>the</strong>mum, but <strong>the</strong> exact<br />
nature of this association is disputed (Kovács et al. 2003). They<br />
apparently disperse by wind after drying in situ, ra<strong>the</strong>r than<br />
relying on an animal vec<strong>to</strong>r. The species are prized as food<br />
items, and Rayss (1959, as cited in Alsheikh & Trappe 1983a)<br />
suggested that <strong>the</strong> manna that fed <strong>the</strong> Israelites could have<br />
been Tirmania truffles. Moreno et al. (2000) reported smooth<br />
spores in T. nivea and a fine net-like ornament on T. pinoyi<br />
spores. See also <strong>the</strong> descriptions in Malençon (1973) and in<br />
Montecchi & Sarasini (2000). Diéz et al. (2002) studied a number<br />
of desert truffles by molecular phylogenetic analyses, and<br />
concluded that <strong>the</strong> sampled species formed a monophyletic<br />
group. Trappe (1979) transferred <strong>the</strong> genus <strong>to</strong> <strong>the</strong> Pezizaceae
1086 T. Læssøe, K. Hansen<br />
based on <strong>the</strong> amyloid asci. Our analyses place Tirmania in <strong>the</strong><br />
P. depressa–Ruhlandiella lineage.<br />
Lineage B<br />
The monotypic, parasitic Rhizinaceae and Caloscyphaceae have<br />
no known hypogeous representatives. <strong>Truffle</strong>s forming<br />
ptycho<strong>the</strong>cia and stereo<strong>the</strong>cia are identified in both <strong>the</strong><br />
Morchellaceae–Discinaceae and Helvellaceae–Tuberaceae lineages<br />
(Figs 3, 6A-H). The family Tuberaceae is unique in its high diversity<br />
of strictly hypogeous taxa.<br />
Morchellaceae–Discinaceae<br />
O’Donnell et al. (1997) placed Leucangium and Fischerula as<br />
incertae sedis due <strong>to</strong> suspected long-branch attraction between<br />
<strong>the</strong>se taxa. Additional sampling of hypogeous taxa in this<br />
group, including <strong>the</strong> type species of Fischerula, could possibly<br />
help resolve this problem.<br />
Fischerula Mattir. 1928 (Fig 6A)<br />
Type: Fischerula macrospora.<br />
Mattirolo (1928) and Knapp (1951) separated Fischerula from<br />
Tuber based on <strong>the</strong> peculiar spore ornamentation and <strong>the</strong><br />
more or less fusiform asci. Trappe (1975b, 1979) placed Fischerula<br />
in <strong>the</strong> Helvellaceae, a placement that can be rejected as long<br />
as <strong>the</strong> two known species are considered congeneric. The<br />
ascoma of <strong>the</strong> American taxon, F. subcaulis, has a stipe-like<br />
extension, as <strong>the</strong> name indicates, which is absent on <strong>the</strong><br />
European taxon.<br />
Leucangium Quél. 1883<br />
Type: Leucangium ophthalmosporum (syn. L. carthusianum).<br />
Li (1997) studied <strong>the</strong> ultrastructure of Leucangium carthusianum,<br />
often treated within Picoa, and found it <strong>to</strong> be close <strong>to</strong> species<br />
in Morchellaceae and Helvellaceae. The structure of <strong>the</strong><br />
excipulum also indicated such a relationship. Li found <strong>the</strong> ascospores<br />
<strong>to</strong> be multi-nucleate, which would point <strong>to</strong>wards <strong>the</strong><br />
Morchellaceae ra<strong>the</strong>r than <strong>the</strong> Helvellaceae. Likewise, O’Donnell<br />
et al. (1997) found that L. carthusianum clustered in <strong>the</strong> neighbourhood<br />
of <strong>the</strong> Morchellaceae, while <strong>the</strong> type of Picoa clustered<br />
with Otidea (Pyronemataceae) (data not shown in O’Donnell et al.<br />
1997). L. carthusianum has apiculate-fusiform ascospores in<br />
saccate asci. Palfner & Agerer (1998b) described <strong>the</strong> ec<strong>to</strong>mycorrhizae<br />
of this species.<br />
Discinaceae Benedix 1961 (syn. Hydnotryaceae M. Lange 1956)<br />
Besides <strong>the</strong> epigeous taxa Discina, Pseudorhizina and Gyromitra,<br />
this family also includes <strong>the</strong> hypogeous taxon Hydnotrya<br />
(O’Donnell et al. 1997)(Figs 3, and 6C-D). The family name Hydnotryaceae<br />
has been used <strong>to</strong> replace Pseudotuberaceae (nom.<br />
inval., Art. 36.1) (e.g. Burdsall 1968), but is itself invalid (no<br />
Latin nor any o<strong>the</strong>r kind of diagnosis, e.g. Art. 36.1).<br />
Hydnotrya Berk. & Broome 1846 (syn. Geoporella, Gyrocratera)<br />
(Figs 6C-D)<br />
Type: Hydnotrya tulasnei.<br />
Knapp (1950, 1952) discussed <strong>the</strong> genus, including <strong>the</strong> synonym<br />
Geoporella, and gave a fairly detailed description, whilst<br />
a thorough key with a few misplaced taxa can be found in<br />
Gilkey (1954). Trappe (1975c) dealt with <strong>the</strong> generic names<br />
Geoporella and Gyrocratera. Trappe (1979), Donadini (1986b)<br />
and later Abbott & Currah (1997) accepted <strong>the</strong> genus in <strong>the</strong><br />
Helvellaceae, which cannot be confirmed by <strong>the</strong> molecular<br />
data. Donadini (1986a) reported 4-nucleate spores. The morphological<br />
variation within <strong>the</strong> genus spans more or less hollow<br />
ascomata with cylindrical asci <strong>to</strong> nearly solid ascomata<br />
(Figs 6C-D) with clavate-saccate asci. There is likewise a great<br />
variation in spore shape and ornamentation. Whe<strong>the</strong>r <strong>the</strong> variation<br />
in spore characters should be given taxonomic importance<br />
in generic assignment awaits fur<strong>the</strong>r molecular data.<br />
Zhang (1991b) demonstrated that <strong>the</strong>re is a conspicuous, but<br />
non-functional, opening in <strong>the</strong> ascus apex of H. cerebriformis.<br />
Gymnohydnotrya B.C. Zhang & Minter 1989<br />
Type: Gymnohydnotrya australiana.<br />
Zhang & Minter (1989b) accepted three Australian species<br />
and placed <strong>the</strong> genus in <strong>the</strong> Helvellaceae based on <strong>the</strong> four nuclei<br />
in <strong>the</strong> spores. The main diagnostic feature was <strong>the</strong> lack of<br />
a peridium, an external, and in <strong>the</strong> type species also internal<br />
hymenium, and <strong>the</strong> non-pigmented spores with an unusual<br />
and intricate ornamentation (a complex reticulum) as<br />
revealed by SEM. Vizzini (2003) lists this genus in <strong>the</strong> Discinaceae<br />
based on <strong>the</strong> similarity <strong>to</strong> Hydnotrya and <strong>the</strong> 4-nucleate<br />
ascospores. There are no published LSU sequences available<br />
for phylogenetic analysis. Two of <strong>the</strong> species had previously<br />
been placed in Sphaerozone (Bea<strong>to</strong>n & Weste 1978).<br />
Helvellaceae Fr. 1823 (syn. Balsamiaceae E. Fisch. 1897)<br />
The Balsamiaceae, a family accepted in an emended version<br />
by Trappe (1979) and by e.g. Pegler et al. (1993), were considered<br />
a synonym of <strong>the</strong> Helvellaceae by van Brummelen (in<br />
Dissing & Schumacher 1994) and in an emended version by<br />
O’Donnell et al. (1997), a conclusion that was followed by<br />
e.g. Eriksson & Winka (1998) and Hansen & Knudsen (2000).<br />
Analyses of LSU identified a Balsamia–Barssia lineage (PB 91 %<br />
and PP 100 %) as a poorly supported sister group <strong>to</strong> a<br />
Helvella–Wynnella lineage (Fig 3). However, this relationship<br />
was highly supported in combined analyses of LSU and SSU<br />
(PB 100 %, O’Donnell et al. 1997; Hansen & Pfister 2007).<br />
Balsamia Vittad. 1831 (syn. Pseudobalsamia E. Fisch.) (Fig 6E)<br />
Type (lec<strong>to</strong>): Balsamia vulgaris.<br />
Knapp (1950) gave a detailed account of this genus, which he<br />
placed in ‘section B’ of his own (invalid; Art. 36.1) family<br />
Pseudotuberaceae, but he later (Knapp 1952) placed it in his<br />
‘Eu-tuberaceae’, based on fur<strong>the</strong>r developmental studies; a<br />
conclusion also reached by Hawker (1954). Donadini (1986b) observed<br />
four nuclei in mature spores and proposed a placement<br />
in <strong>the</strong> Helvellaceae. The asci can be more or less organized in<br />
a palisade-like structure. Morphologically, Balsamia species<br />
are typical truffles with closed fruit bodies with a veined interior<br />
and a coarse peridium (Fig 6E). The asci are sac-like with<br />
clustered spores. The spore morphology is simple as in many<br />
species of Helvella. Species delimitation has been a subject of<br />
discussion with Szemere (1965) taking a very broad view.<br />
Trappe (1975c) agreed that Pseudobalsamia should be placed in<br />
synonymy with Balsamia. Palfner & Agerer (1998a) described<br />
<strong>the</strong> ec<strong>to</strong>mycorrhiza formed between B. alba and Pseudotsuga.<br />
Barssia Gilkey 1925<br />
Type: Barssia oregonensis.
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1087<br />
Fig 6 – Fruiting body forms in lineage B (Morchellaceae-Discinaceae-Helvellaceae-Tuberaceae). (A) Fischerula macrospora,<br />
solid ptycho<strong>the</strong>cium. (B) Choiromyces venosus, solid ptycho<strong>the</strong>cium. (C) Hydnotrya tulasnei, ptycho<strong>the</strong>cia, JV87-356 (C).<br />
(D) Hydnotrya michaelis, ptycho<strong>the</strong>cia, JHP-00.018 (C). (E) Balsamia polysperma, ptycho<strong>the</strong>cia, JV97-080 (C). (F) Helvella astieri,<br />
ptycho<strong>the</strong>cia, (C-65663). (G) Tuber aestivum, stereo<strong>the</strong>cia, JHP-00.395. (H) Tuber rufum, stereo<strong>the</strong>cia, JV93-321(C). Pho<strong>to</strong>s:<br />
J. San<strong>to</strong>s (A), J.H. Petersen (B, D, G detail), J. Vesterholt (C, E, H), T. Læssøe (F), C. Lange (G).
1088 T. Læssøe, K. Hansen<br />
Kimbrough et al. (1996) studied <strong>the</strong> ultrastructure of <strong>the</strong> type<br />
species. Trappe (1979) included ano<strong>the</strong>r monotypic genus, Phyma<strong>to</strong>myces,<br />
in Barssia, but as <strong>the</strong> type has been lost, this<br />
Japanese taxon should be re-investigated. Barssia ascomata<br />
have a smoo<strong>the</strong>r surface compared <strong>to</strong> species of Balsamia.<br />
Molecular results indicate a very close relationship between<br />
Barssia and Balsamia, so that it may be a sound move <strong>to</strong><br />
synonymize <strong>the</strong>se genera, but more taxa, including <strong>the</strong> type<br />
of Balsamia, should be sampled before such a decision is made.<br />
Helvella L. 1753: Fr.<br />
Helvella astieri Korf & Donadini (Fig 6F) (Korf 1973b) is <strong>the</strong><br />
only known truffle within <strong>the</strong> genus. No molecular data are<br />
available for H. astieri, but its placement in Helvella is convincing<br />
on morphological grounds. It has closed semi-hypogeous<br />
fruit bodies and apparently passive spore dispersal, but an<br />
operculum is still present. The species is very rarely recorded,<br />
but is known from France and Denmark (Hansen & Knudsen<br />
2000). The similarity of H. astieri and species of Hydnotrya<br />
was used in placing Hydnotrya in <strong>the</strong> Helvellaceae (Trappe<br />
1979; Pegler et al. 1993). Trappe (1979): ‘Korf in effect emended<br />
<strong>the</strong> family (Helvellaceae) <strong>to</strong> include astipitate, infolded and<br />
chambered ascomata by <strong>the</strong> description of Helvella astieri<br />
Korf & Donadini. This species is essentially a Hydnotrya with<br />
operculate asci and hyaline spores’. This view was strongly<br />
opposed by Donadini (1986a), as he found spores, paraphyses<br />
and excipulum exactly as in Helvella.<br />
Insufficient data [placed here in Eriksson (2006a)]:<br />
Picoa Vittad. 1831<br />
Type: Picoa juniperi.<br />
This genus was placed in <strong>the</strong> Balsamicaeae by e.g. Trappe<br />
(1979) and likewise in Montecchi & Sarasini (2000). Some species<br />
have asci arranged in a clear palisade, whereas in o<strong>the</strong>rs<br />
<strong>the</strong> asci are more dispersed. The genus can be difficult <strong>to</strong> differentiate<br />
from Balsamia based on <strong>the</strong> characters employed<br />
e.g. by Montecchi & Sarasini (2000). Preliminary LSU rDNA sequence<br />
data of P. juniperi, suggest it is more closely related <strong>to</strong><br />
Otidea (unpublished data in O’Donnell et al. 1997) than <strong>to</strong> <strong>the</strong><br />
taxa in clade B (as sampled by O’Donnell et al. 1997).<br />
Tuberaceae Dumort. 1822<br />
Only hypogeous taxa cluster alongside <strong>the</strong> likewise hypogeous<br />
genus Tuber. Ascomata produced by <strong>the</strong> Dingleya–<br />
Choiromyces lineage show a persistent hymenium (chambered<br />
<strong>to</strong> completely compressed ptycho<strong>the</strong>cia), whereas ascomata<br />
produced by Tuber spp. have lost <strong>the</strong> hymenium (stereo<strong>the</strong>cia).<br />
Tuber is <strong>the</strong> most speciose genus of ascomyce<strong>to</strong>us truffles,<br />
and it is known from many areas around <strong>the</strong> world,<br />
including North America, Central America, Europe, and Asia,<br />
but apparently not from subsaharan Africa and South America.<br />
It has been introduced <strong>to</strong> Australia (Bougher & Lebel<br />
2001). Dingleya, Reddellomyces, and Labyrinthomyces clearly<br />
have a centre of diversity in Australia and New Zealand.<br />
Choiromyces Vittad. 1831 (syn. e.g. Piersonia) (Fig 6B)<br />
Type: Choiromyces meandriformis (syn. C.venosus)<br />
Although often placed in <strong>the</strong> Helvellaceae (e.g. in Pegler et al.<br />
1993) current molecular phylogenies place <strong>the</strong> type species as<br />
a sister <strong>to</strong> Tuber, making it possible <strong>to</strong> include it in <strong>the</strong> Tuberaceae<br />
(O’Donnell et al. 1997). Gilkey (1955) and also Korf<br />
(1973a) suggested this placement, whereas Hawker (1954)<br />
and o<strong>the</strong>rs (e.g. Trappe 1979) placed <strong>the</strong> genus in <strong>the</strong> Terfeziaceae<br />
based on structural studies. Zhang & Minter (1989a) studied<br />
C. gangliformis (considered by some, e.g. Montecchi &<br />
Sarasini (2000), as a possible synonym of C. meandriformis) in<br />
detail and found four nuclei in <strong>the</strong> spores, which could<br />
indicate <strong>the</strong> Helvellaceae. However, 4-nucleate spores are also<br />
commonly found in Tuber. Zhang & Minter (1989a) found<br />
multi-layered ascus walls in taxa belonging <strong>to</strong> Choiromyces as<br />
opposed <strong>to</strong> taxa of f.ex. Terfezia. This complex wall system<br />
would appear <strong>to</strong> characterize taxa in <strong>the</strong> Tuberaceae. They<br />
also emphasized <strong>the</strong> strange, pitted spore ornamentation.<br />
Dingleya Trappe 1979, emend. Trappe, Castellano &<br />
Malajczuk 1992<br />
Type: Dingleya verrucosa.<br />
The genus was described from New Zealand and stated <strong>to</strong><br />
differ from Hydnotrya species by having a more solid, but<br />
apparently still chambered gleba and a verrucose peridium.<br />
Later, <strong>the</strong> affinities were considered <strong>to</strong> be with Reddellomyces<br />
and Labyrinthomyces (Trappe et al. 1992), which our analyses<br />
confirm (Fig 3). Trappe et al. (1992) recognized six species. It<br />
is not unlikely that in a future revision <strong>the</strong> three genera will<br />
be lumped.<br />
Labyrinthomyces Boedijn 1939, emend. Trappe, Castellano &<br />
Malajczuk 1992<br />
Type: Labyrinthomyces varius.<br />
Trappe et al. (1992) accepted this genus within <strong>the</strong> Pyronemataceae<br />
s.l. (as tribe Otideae or undescribed tribe), but <strong>the</strong><br />
type species is highly supported within Tuberaceae in molecular<br />
phylogenies (O’Donnell et al. 1997) (Fig 3). There is a strong<br />
relation <strong>to</strong> Reddellomyces and Dingleya (PB 95 %, PP 100 %).<br />
Zhang & Minter (1988), Bea<strong>to</strong>n & Weste (1977), and Malençon<br />
(1973) also discussed <strong>the</strong> status of this genus, but <strong>the</strong>ir concept<br />
included Dingleya and Reddellomyces, whereas Trappe et al.<br />
(1992) restricted <strong>the</strong> genus <strong>to</strong> <strong>the</strong> type species.<br />
Paradoxa Mattir. 1935<br />
Type: Paradoxa monospora.<br />
Knapp (1951) discussed this genus and declared ‘Stellung<br />
dieses Genus ist noch unsicher’. Vizzini (2003) indicated<br />
that it nests within <strong>the</strong> genus Tuber (data not shown). It is<br />
normally included in <strong>the</strong> Tuberaceae (e.g. Montecchi & Sarasini<br />
2000; Castellano et al. 2004). As <strong>the</strong> name indicates this<br />
Italian truffle has 1-spored asci, and <strong>the</strong> globose spores<br />
have a low, net-like ornament. The ascoma surface is fibrillose<br />
from closely packed hyphae. We accept it ad interim<br />
within <strong>the</strong> Tuberaceae.<br />
Reddellomyces Trappe, Castellano & Malajczuk 1992 (syn.<br />
Labyrinthomyces subgen. Simplex)<br />
Type: Reddellomyces westraliensis.<br />
Trappe et al. (1992) separated this taxon from Labyrinthomyces<br />
and Dingleya based on a smooth and glabrous peridium and<br />
asci with 1–5 spores. They accepted four species. Our analyses<br />
of existing sequences indicate a close relationship between<br />
Labyrinthomyces, Dingleya, and Reddellomyces, a group of taxa
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1089<br />
that Malençon (1973) treated in an expanded version of<br />
Labyrinthomyces. Trappe et al. (1992) considered <strong>the</strong>se taxa <strong>to</strong><br />
belong <strong>to</strong> <strong>the</strong> Pyronemataceae (but in different tribes), but as<br />
can be seen from Fig 3, <strong>the</strong>y clearly are close <strong>to</strong> Tuber, and<br />
maybe <strong>the</strong>y should be united under Labyrinthomyces.<br />
Tuber F.H. Wigg. 1780: Fr. (syn. Aschion, Ensaluta, Oogaster,<br />
Lespiaultinia, Delastreopsis, Terfeziopsis, Mukagomyces)<br />
(Figs 6G-H)<br />
Type: Tuber gulosorum. [This name is currently not unders<strong>to</strong>od<br />
and is open <strong>to</strong> interpretation, but most likely represents<br />
T. aestivum Vittad. 1831 (Fig 6G). Various o<strong>the</strong>r typifications are<br />
given in <strong>the</strong> literature, including Index Fungorum, which lists<br />
T. aestivum. A conservation procedure will probably be needed<br />
<strong>to</strong> solve this problem, as Trappe (2001) points out <strong>the</strong> sanctioned<br />
T. albidum also represents T. aestivum].<br />
The apo<strong>the</strong>cial nature of <strong>the</strong> primordial Tuber ascomata has<br />
long been known (e.g. Parguey-Leduc et al. 1990; Janex-Favre &<br />
Parguey-Leduc 2002, 2003) and in some species this can even<br />
be hinted at in mature specimens. Parguey-Leduc et al. (1987a,<br />
1987b) studied asci and spores of T. melanosporum in ultrastructural<br />
detail. Li & Kimbrough (1995) studied ultrastructural<br />
characters and supported a placement within Pezizales. The<br />
characters found were so divergent that <strong>the</strong>y suggested that<br />
Tuber could be polyphyletic. A Geniculodendron-like anamorph<br />
has been reported from Tuber dryophilum (Urban et al. 2002). It is<br />
a big genus with 63 species according <strong>to</strong> Kirk et al. (2001). The genus<br />
forms a ra<strong>the</strong>r diverse group with a well-supported separate<br />
position within <strong>the</strong> present phylogenetic analysis (Fig 3). The<br />
synonymy cited above is according <strong>to</strong> Trappe (1975c, 1979).<br />
Janex-Favre & Parguey-Leduc (2002) apparently recognized <strong>the</strong><br />
genus Delastreopsis. The multinuclear condition of <strong>the</strong> mature<br />
spores is a well-known character in some species of Tuber (e.g.<br />
Donadini 1987). Mello et al. (2005) investigated <strong>the</strong> white (Piedmont)<br />
truffle (T. magnatum) in detail anddiscussed various explanations<br />
for <strong>the</strong> nuclear condition. Vizzini (2003) indicated that<br />
most species have four nuclei in <strong>the</strong> majority of <strong>the</strong> ascospores,<br />
whereas a few species have less or more nuclei in <strong>the</strong> spores. Recently,<br />
Wedén et al. (2005) tested whe<strong>the</strong>r <strong>the</strong> height of <strong>the</strong> spore<br />
ornament can be used (as has been claimed) <strong>to</strong> distinguish two<br />
disputed truffles T. aestivum and T. uncinatum. All samples<br />
formed a single fully supported group and <strong>the</strong> names should<br />
be treated as synonyms, thus confirming <strong>the</strong> conclusion reached<br />
by some early workers (e.g. Hawker 1954). Kovács & Jakucs (2006)<br />
published a detailed phylogenetic and ana<strong>to</strong>mical paper on <strong>what</strong><br />
<strong>the</strong>y termed <strong>the</strong> white truffles. Papers describing Tuber mycorrhizae<br />
include Blaschke (1987), Rauscher et al. (1995) and Zambonelli<br />
et al. (1993, 1999). Chevalier & Frochot (1997) published<br />
a whole book on <strong>the</strong> Burgundy truffle, a name traditionally attached<br />
<strong>to</strong> T. uncinatum, now considered a synonym of T. aestivum<br />
(Wedén et al. 2005). The review of Tuber by Ceruti et al. (2003)<br />
should also be consulted. Roux et al. (1999) compared some Chinese<br />
and European truffles based on molecular studies. A suite of<br />
new species is currently being discovered and described in China<br />
(e.g. He et al. 2004). Trappe et al. (1996) provided a key <strong>to</strong> Tuber species<br />
with a spiny-reticulate spore ornament. There is an ongoing<br />
project <strong>to</strong> stabilize <strong>the</strong> use of Tuber names (e.g. Mello et al. 2000).<br />
Insufficient data [In Eriksson (2006a) placed in Pezizales incertae<br />
sedis]:<br />
Loculotuber Trappe, Parladé & I.F. Alvarez 1993<br />
Type: Loculotuber gennadii.<br />
The authors (Alvarez et al. 1993) stated this monotypic<br />
genus <strong>to</strong> differ from Tuber in having glebal locules and stipitate<br />
asci. The spores tend <strong>to</strong> become citriform. They speculated<br />
that <strong>the</strong> genus formed an intermediate between an<br />
unknown epigeous member of <strong>the</strong> Pezizales and <strong>the</strong> genus<br />
Tuber. Castellano et al. (2004) listed this genus in <strong>the</strong> Tuberaceae.<br />
Lineage C<br />
The presumably strictly saprotrophic families Ascodesmidaceae,<br />
Sarcoscyphaceae and Sarcosomataceae have no known<br />
hypogeous representatives. Glaziellaceae are suggested <strong>to</strong> belong<br />
<strong>to</strong> this clade (Hansen & Pfister 2007; Perry et al. 2007)<br />
(Figs 4 and 7A-H).<br />
Glaziellaceae J.L. Gibson 1986<br />
Glaziella Berk. 1880<br />
Type: Glaziella vesiculosa Berk (syn. G. aurantiaca).<br />
This genus is unusual in several respects. It fruits more or<br />
less on <strong>to</strong>p of <strong>the</strong> soil and is completely hollow with a ra<strong>the</strong>r<br />
thin rind that contains <strong>the</strong> monosporic asci, <strong>the</strong> spore being<br />
enormous. The only species Glaziella aurantiaca (Fig 7A) has<br />
been interpreted in many ways, including a placement in<br />
Xylaria (Sordariomycetes, Ascomycota), in <strong>the</strong> Zygomycota and finally<br />
in <strong>the</strong> Pezizales. An early molecular study (Landvik &<br />
Eriksson 1994b) suggested a relationship with members of<br />
<strong>the</strong> Pyronemataceae. Later Landvik et al. (1997) expanded on<br />
this and found fur<strong>the</strong>r evidence, but still based on a very limited<br />
taxon sampling, for a relationship (low support) with e.g.<br />
Pulvinula and <strong>the</strong> likewise semi-hypogeous genus Paurocotylis.<br />
They ad interim accepted Glaziellaceae but not Glaziellales. Harring<strong>to</strong>n<br />
et al. (1999) found support for inclusion in <strong>the</strong> Pezizales,<br />
but did not resolve a position within, although <strong>the</strong>ir results<br />
could indicate a closer relationship with <strong>the</strong> Sarcoscyphaceae<br />
ra<strong>the</strong>r than with <strong>the</strong> Pyronemataceae. They erroneously cited<br />
<strong>the</strong> origin of <strong>the</strong> specimen as Sweden. Castellano et al. (2004)<br />
maintained a placement in <strong>the</strong> Glaziellales. Perry et al. (2007)<br />
had Glaziellaceae in a sister position <strong>to</strong> Pyronemataceae but<br />
with low statistical support. Eriksson (2006a) accepts <strong>the</strong> family<br />
in Pezizales. At least some collections of this pantropical<br />
taxon are from decidedly ec<strong>to</strong>trophic communities, but <strong>the</strong><br />
exact nature of its biology is not known.<br />
Pyronemataceae Schröter 1894 (syn. Geneaceae)<br />
This family has been defined as having 1-nucleate ascospores<br />
and non-amyloid asci. It has relatively few hypogeous<br />
members with Genea as <strong>the</strong> most prominent genus. Geopora<br />
is represented with just one species that only pro parte qualifies<br />
as a truffle (active spore dispersal not completely lost). Fur<strong>the</strong>rmore,<br />
with <strong>the</strong> exception of Paurocotylis, <strong>the</strong> truffles<br />
formed in Pyronemataceae all still possess a hymenium; no<br />
stereo<strong>the</strong>cia are found. Epigeous members have both saprotrophic<br />
and mycorrhizal representatives, but Paurocotylis<br />
would seem <strong>to</strong> be <strong>the</strong> only saprotrophic hypogeous member.<br />
Although Geneaceae have gained wide acceptance, it can be<br />
concluded both by morphological studies by e.g. Pfister<br />
(1984) and Zhang (1992a), and molecular studies (Perry et al.<br />
2007) (Fig 4), that it is part of Pyronemataceae as currently<br />
circumscribed.
1090 T. Læssøe, K. Hansen<br />
Fig 7 – Fruiting body forms in lineage C (Glaziellaceae-Pyronemataceae). (A) Glaziella aurantiaca, unnamed ascoma type,<br />
TL-6168 (C). (B) Genea fragrans, ptycho<strong>the</strong>cia, JV99-373 (C). (C) Humaria hemisphaerica, apo<strong>the</strong>cia, JHP-03.144. (D) Genabea<br />
cerebriformis, ptycho<strong>the</strong>cia. (E) Geopora cooperi, ptycho<strong>the</strong>cia. (F) Geopora arenicola, apo<strong>the</strong>cia, JHP-93.114 (C). (G) Hydnocystis<br />
clausa, ptycho<strong>the</strong>cia, PH00-192 (C). (H) Stephensia bombycina, ptycho<strong>the</strong>cia. Pho<strong>to</strong>s: T. Læssøe (A), J. Vesterholt (B, G), J.H.<br />
Petersen (C, F), M. Tabarés (D), J. Nitare (E, H).
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1091<br />
Genea Vittad. 1831 (syn. Hydnocaryon)<br />
Type (lec<strong>to</strong>type): Genea verrucosa.<br />
In Genea <strong>the</strong> ascomata have a more or less obvious opening,<br />
and can be unfolded <strong>to</strong> strongly folded (ptycho<strong>the</strong>cia; Fig 7B).<br />
The asci are arranged in hymenia, but active spore dispersal<br />
has been completely lost. The tips of <strong>the</strong> paraphyses have<br />
fused <strong>to</strong> form an epi<strong>the</strong>cium that protects <strong>the</strong> hymenium (Gilkey<br />
1954). The more or less hyaline spores have a very prominent<br />
ornamentation. Trappe (1979) accepted 29 species. Li &<br />
Kimbrough (1994) studied <strong>the</strong> ultrastructure that compared<br />
with members of <strong>the</strong> Pyronemataceae s.l. (as Otideaceae). Phylogenetic<br />
analyses of LSU rDNA support <strong>the</strong> placement in Pyronemataceae,<br />
and suggest that Genea is closely related <strong>to</strong><br />
Humaria hemisphaerica (Figs 7B-C) (Perry et al. 2007) (PB and<br />
PP 100 %, Figs 4). Pfister (1984) proposed <strong>to</strong> place G. hispidula<br />
in Humaria based on analysis of excipular structures. Like species<br />
of Genea, H. hemisphaerica has also been shown <strong>to</strong> be ec<strong>to</strong>mycorrhizal<br />
(Tedersoo et al. 2006).<br />
Smith et al. (2006) studied <strong>the</strong> phylogeny, morphology,<br />
and taxonomy of a group of Quercus-associated species and<br />
listed some minor differences between Genea and <strong>the</strong> closely<br />
related Genabea (Fig 7D) and Gilkeya. They added a couple of<br />
new species.<br />
Genabea Tul. & C. Tul. 1844 (syn. Myrmecocystis, Pseudogenea)<br />
Type: Genabea fragilis.<br />
The genus was accepted by Trappe (1975c) and again by<br />
Smith et al. (2006). It differs from Genea in having clavate <strong>to</strong> ellipsoid<br />
asci in hymenia enclosed in pockets, and in having<br />
echinulate spores ra<strong>the</strong>r than verrucose. Index Fungorum lists<br />
five binomials, two based on European material, two on North<br />
American, and one on Tasmanian. Zhang (1991a) placed<br />
Genabea in synonymy with Genea, which Korf (1973a) also had<br />
suggested. Smith et al. (2006) only dealt with one species, G. cerebriformis<br />
(Fig 7D), that clustered separately from <strong>the</strong> included<br />
Genea species based on LSU data. However, <strong>the</strong> type species of<br />
Genabea has not been sampled for molecular phylogenetic<br />
studies, which are needed in order <strong>to</strong> fully test <strong>the</strong> delimitation<br />
of Genabea, Myrmecocystis (type: M. cerebriformis) and Genea.<br />
Trappe (1975c) synonymized Myrmecocystis with Genabea.<br />
Geopora Harkn. 1885 (syn. Sepultaria, Pseudohydnotrya)<br />
Type: Geopora cooperi.<br />
Burdsall (1965, 1968) studied this genus in detail and combined<br />
Sepultaria with Geopora after having found actively discharged<br />
spores in <strong>the</strong> type species of Geopora. Korf (1973b)<br />
gave a detailed review. Biologically G. cooperi (Fig 7E) behaves<br />
like an ordinary truffle but <strong>the</strong> operculum and <strong>the</strong> build up<br />
of internal pressure within mature asci have not been lost.<br />
O<strong>the</strong>r species develop in <strong>the</strong> soil but open at <strong>the</strong> surface at<br />
maturity (Fig 7F). Nannfeldt (1946) also gave a rarely cited, but<br />
detailed summary (in Swedish) of <strong>the</strong> Geopora situation. He<br />
regarded G. cooperi (as G. schackii) as a truffle based on biological<br />
arguments, such as passive animal dispersal, smell, etc.<br />
Trappe (1975c) agreed on <strong>the</strong> above synonymy. Phylogenetic<br />
analyses of LSU confirm <strong>the</strong> placement of G. cooperi among<br />
epigeous Geopora spp. (PB and PP 100 %, Fig 4).<br />
Gilkeya M.E. Sm., Trappe & Rizzo 2006<br />
Type: Hydnocystis compacta (Gilkeya compacta).<br />
This genus was erected based on a separate, although unresolved,<br />
position of Hydnocystis compacta in a LSU analysis of<br />
Genea (over six) and Genabea (one) species (H. compacta formed<br />
a tricho<strong>to</strong>my with Genea and Genabea), in combination with a deviating<br />
reddish peridium colour compared with species of Genea<br />
and Genabea. A similar molecular result was found by Perry et al.<br />
(2007) with Gilkeya and Genabea as (unsupported) successive sister<br />
taxa <strong>to</strong> a highly supported Genea–Humaria hemisphaerica<br />
clade. Fur<strong>the</strong>r taxon sampling will hopefully resolve its position<br />
in a clearer way. Gilkeya and Genabea differ from Genea in having<br />
globose spores and <strong>the</strong> ascomata lack a basal tuft of mycelium.<br />
Hydnocystis Tul. & C. Tul. 1844 (syn. Pro<strong>to</strong>genea)<br />
Type: Hydnocystis piligera.<br />
Burdsall (1968) gave a detailed taxonomic and nomenclatural<br />
account of <strong>what</strong> he considered <strong>the</strong> only species of Hydnocystis,<br />
H. piligera. The genus is morphologically characterized<br />
by its bladder-like hypogeous ascomata with a hairy, sandbinding<br />
outer surface and an irregular opening <strong>to</strong> <strong>the</strong> outside.<br />
The spores are globose, eguttulate, and an epi<strong>the</strong>cium is present.<br />
We accept its current position in <strong>the</strong> Pyronemataceae based<br />
on morphological characters. No sequences are available.<br />
Senn-Irlet & Aeberhard (2005) reviewed <strong>the</strong> genus in a<br />
European context, and stated that <strong>the</strong> ec<strong>to</strong>mycorrhizal status<br />
of this fungus is uncertain. The placement of <strong>the</strong> species<br />
H. clausa (Fig 7G) is disputed. Burdsall (1968) placed it in Geopora;<br />
o<strong>the</strong>rs have placed it with Hydnocystis (Montecchi & Sarasini<br />
2000). Trappe (1975c) studied <strong>the</strong> type of Pro<strong>to</strong>genea and proposed<br />
<strong>the</strong> above synonymy. Hydnocystis singeri from Argentina<br />
was discussed in Burdsall (1968). It was not accepted in <strong>the</strong> genus,<br />
but compared with Labyrinthomyces and Phyma<strong>to</strong>myces. It<br />
was thought <strong>to</strong> possibly represent a new genus. It is one of<br />
very few ascomyce<strong>to</strong>us truffles reported from South America.<br />
Paurocotylis Berk. 1855<br />
Type: Paurocotylis pila.<br />
Pa<strong>to</strong>uillard (1903) was <strong>the</strong> first <strong>to</strong> recognize that <strong>the</strong> type<br />
and only recognized species belongs <strong>to</strong> Ascomycota. The bright<br />
red pigmentation points <strong>to</strong> a relationship with carotenoid<br />
members of <strong>the</strong> Pyrenomataceae. Trappe (1979: 321) wrote ‘it<br />
suggests an aleurioid fungus gone underground and fits nicely<br />
in tribe Aleurieae sensu Korf’. Pa<strong>to</strong>uillard (1903) indicated a<br />
position close <strong>to</strong> Hydnocystis, and noted that <strong>the</strong> remaining<br />
taxa belong elsewhere. Paurocotylis pila forms a monophyletic<br />
group with Stephensia, Geopyxis, and Tarzetta species (PB 99 %<br />
and PP 100 %, Fig 4). Originally, <strong>the</strong> microscopical similarity between<br />
Paurocotylis and Stephensia was noted. The exact nature<br />
of its ecology is far from unders<strong>to</strong>od. It is considered a native<br />
of New Zealand and an introduction <strong>to</strong> <strong>the</strong> UK (Dennis 1975).<br />
It is now fairly common in <strong>the</strong> nor<strong>the</strong>rn parts of <strong>the</strong> UK, not<br />
least in Orkney (Eggerling 2004), where it fruits during <strong>the</strong> wintertime<br />
in highly disturbed soils, in vegetable plots, along<br />
roads, etc. As noted above, it has been suggested that <strong>the</strong> bright<br />
red colour may attract birds (ground-dwelling species that fulfil<br />
<strong>the</strong> small mammal niche in New Zealand) that may act as dispersal<br />
vec<strong>to</strong>rs in its natural setting (Castellano et al. 2004). Macromorphologically<br />
it resembles Glaziella (Fig 7A), which also<br />
has hollow ascomata, that occur more or less on <strong>to</strong>p of <strong>the</strong><br />
soil (see separate entry). Dennis (1975) noted that Paurocotylis<br />
spores in mature ascomata are cream coloured and found in
1092 T. Læssøe, K. Hansen<br />
a powdery mass entangled with hyphae. Castellano et al. (2004)<br />
list Paurocotylis as a saprotrophic fungus, and also Dennis (1975)<br />
noted that no obvious mycorrhizal host was found in connection<br />
with <strong>the</strong> first UK find. However, <strong>the</strong> o<strong>the</strong>r members of<br />
<strong>the</strong> clade, e.g. Geopyxis carbonaria (Vra˚lstad et al. 1998) and<br />
Tarzetta (Tedersoo et al. 2006), have been shown <strong>to</strong> be<br />
ec<strong>to</strong>mycorrhizal.<br />
Petchiomyces E. Fisch. & Mattir. 1938<br />
Type: Hydnocystis twaitesii (syn. Petchiomyces twaitesii).<br />
This genus was included in Geneaceae by Fischer (1938),<br />
followed by Gilkey (1954). Burdsall (1968) studied <strong>the</strong> type of<br />
<strong>the</strong> type species and concluded that it could not be placed in<br />
Geopora based on <strong>the</strong> presence of an epi<strong>the</strong>cium and ornamented<br />
spores. Gilkey (1939) described Petchiomyces kraspedos<strong>to</strong>ma<br />
from California, <strong>the</strong> only additional species known<br />
besides <strong>the</strong> type from Sri Lanka. P. kraspedos<strong>to</strong>ma has an apical<br />
opening with stiff, incurved hairs and smooth, ellipsoid<br />
spores. The genus should be revised, but we ad interim accept<br />
its position within <strong>the</strong> Pyronemataceae.<br />
Phaeangium Pat. 1894<br />
Type: Phaeangium lefebvrei.<br />
This genus was sunk under Picoa by Maire (1906), but resurrected<br />
by Alsheikh & Trappe (1983b), a move not accepted by<br />
e.g. Moreno et al. (2000). Gutierrez et al. (2003) described <strong>the</strong><br />
ra<strong>the</strong>r deviating mycorrhizae formed by Phaeangium lefebvrei<br />
(as Picoa) with Helian<strong>the</strong>mum species. We ad interim accept<br />
<strong>the</strong> genus (within Pyronemataceae).<br />
Sphaerosoma Klotzsch 1839<br />
Type: Sphaerosoma fuscescens.<br />
Korf (1972) placed <strong>the</strong> genus in <strong>the</strong> Ascobolaceae following<br />
previously published characters and was ad interim followed<br />
by Trappe (1979). Gamundi (1976) could not find any amyloid reaction<br />
in <strong>the</strong> type material and considered it a likely member of<br />
<strong>the</strong> Pyronemataceae (as Humariaceae tribe Otideae). Dissing & Korf<br />
(1980) followed Gamundi but stated ‘studies on fresh material<br />
are needed before <strong>the</strong> true systematic position of this genus<br />
can be evaluated’. They felt, based on circumstantial evidence,<br />
that Sphaerosoma fuscescens probably has forcible spore discharge.<br />
Montecchi & Sarasini (2000) cite Sphaerosoma as a synonym<br />
of <strong>the</strong> younger name Sphaerozone (Pezizaceae!), but it is<br />
accepted in e.g. Vizzini (2003) in <strong>the</strong> Pyronemataceae and ad interim<br />
here. Kirk et al. (2001) stated <strong>the</strong> number of species as<br />
three, but <strong>the</strong>re are 11 names in Index Fungorum currently without<br />
o<strong>the</strong>r placement. A revision would seem <strong>to</strong> be required.<br />
Stephensia Tul. & C. Tul. 1845 (syn. Densocarpa, Elderia)<br />
Type: Stephensia bombycina (Fig 7H).<br />
Knapp (1951) gave a description of <strong>the</strong> type species, whereas<br />
Fontana & Giovannetti (1987) described its anamorph. Uecker<br />
(1967) reported a similar anamorph for Stephensia shanori.<br />
Trappe et al. (1997) published a key <strong>to</strong> <strong>the</strong> species. Our placement<br />
(Fig 4) is based on sequences obtained by Perry et al.<br />
(2007). De Vi<strong>to</strong> (2003) described a new species, S. colomboi, said<br />
<strong>to</strong> differ from previously described species in being epigeous<br />
on rotten wood. Based on <strong>the</strong> published picture <strong>the</strong> wood<br />
more or less qualifies as soil, and some of <strong>the</strong> ascomata appear<br />
<strong>to</strong> be at least partly immersed. Microscopically, S. colomboi is<br />
apparently very close <strong>to</strong> S. bombycina, but some minor macroscopical<br />
differences are noted.<br />
Hypogeous pezizalean taxa currently not placed<br />
within clade A–C<br />
Carbomycetaceae Trappe 1971<br />
Trappe (1971) erected this family as a segregate from Terfeziaceae.<br />
It was based on ‘brown-walled asci borne in fertile<br />
pockets of large, inflated cells mixed with narrow, tubular<br />
ascogenous hyphae, and in <strong>the</strong> fertile pockets being separated<br />
by sterile veins of inflated cells only’. It never produces a hymenium<br />
in any kind of palisade. When dry <strong>the</strong> spore mass becomes<br />
pulverulent almost as in Elaphomyces. Eriksson (2006a)<br />
accepts <strong>the</strong> family in <strong>the</strong> Pezizales.<br />
Carbomyces Gilkey 1954<br />
Type: Carbomyces emergens.<br />
This interesting taxon, only known from three species in<br />
southwestern North America, is currently under study by<br />
K. Hansen using molecular techniques. According <strong>to</strong> Trappe<br />
(1971) its mycorrhizal status has not been clarified. At maturity<br />
<strong>the</strong> ascomata are dispersed by <strong>the</strong> wind (Trappe 1979).<br />
Zak & Whitford (1986) demonstrated <strong>the</strong> hypogeous nature<br />
of immature Carbomyces emergens, and that rodents apparently<br />
eat <strong>the</strong> (immature?) ascomata.<br />
Pezizalean truffles with unknown family placement<br />
(based on Eriksson (2006a)<br />
Delastria Tul. & C. Tul. 1843<br />
Type (mono): Delastria rosea.<br />
Not much is known about this sou<strong>the</strong>rn European/<br />
North African monotypic genus. Montecchi & Sarasini (2000)<br />
include it in <strong>the</strong> Terfeziaceae (here considered a synonym of<br />
<strong>the</strong> Pezizaceae), following Trappe (1979), and differentiate it<br />
from <strong>the</strong> o<strong>the</strong>r accepted genera in this family by <strong>the</strong> evanescent<br />
peridium, <strong>the</strong> pinkish colour of <strong>the</strong> gleba, 2–4-spored<br />
asci and a reticulate spore ornament. Castellano et al. (2004)<br />
accepted <strong>the</strong> genus in <strong>the</strong> Tuberaceae. DNA studies are clearly<br />
needed in order <strong>to</strong> clarify <strong>the</strong> position of this Tuber-like genus.<br />
Unplaced Ascomycota truffles (Eriksson 2006a)<br />
Diehliomyces Gilkey 1955<br />
Type (mono): Diehliomyces microsporus.<br />
This pest in mushroom beds (<strong>the</strong> ‘compost truffle’) is referred<br />
<strong>to</strong> as a ‘false truffle’ in Kirk et al. (2001), but its ascomyce<strong>to</strong>us<br />
nature is not disputed, and it must be considered<br />
a genuine although ra<strong>the</strong>r atypical truffle. Its position is unsettled,<br />
but it could belong in Pezizales and parallel <strong>the</strong> case<br />
of Orbicula, ano<strong>the</strong>r passively discharged, but epigeous fungus<br />
that has led a tumultuous life, but now has found its place in<br />
<strong>the</strong> Pezizales (Hansen et al. 2006). Both genera have had<br />
Eurotiales/Onygenales proposed as proper placements, mainly<br />
due <strong>to</strong> <strong>the</strong> production of small ascomata with small, globose<br />
spores. Unlike almost all o<strong>the</strong>r truffles this species is clearly<br />
not mycorrhizal. Diehl & Lambert (1930) introduced <strong>the</strong><br />
species as Pseudobalsamia microspora after having received material<br />
from an Ohio grower where <strong>the</strong> pest was ‘filling his beds
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1093<br />
and completely s<strong>to</strong>pping <strong>the</strong> production of mushrooms’. It<br />
was later found in o<strong>the</strong>r American sites and later also in<br />
Europe (e.g. Pegler et al. 1993). It resembles many typical<br />
ascomyce<strong>to</strong>us truffles in having a convoluted ascoma up <strong>to</strong><br />
3 cm diam with an outer rind. It may have one or several openings<br />
<strong>to</strong> <strong>the</strong> exterior. The asci are evanescent, long stipitate<br />
with a sac-like, spore-containing part. Unlike typical pezizalean<br />
truffles, <strong>the</strong> spores are smooth and subglobose, 5–7 mm<br />
diam, and form an ‘olivaceous sulphur-coloured dusty mass’<br />
(Diehl & Lambert 1930; Gilkey 1955). Diehl & Lambert (1930)<br />
also reported chlamydospores up <strong>to</strong> 13 mm diam, with a thick,<br />
golden-brown wall. It was grown in artificial culture, where it<br />
produced ascomata. These authors tentatively concluded that<br />
<strong>the</strong> truffle could be considered a weed in mushroom beds<br />
ra<strong>the</strong>r than a parasite of <strong>the</strong> mushrooms. Singer (1961) published<br />
a plate that clearly indicates <strong>the</strong> scale of a full-blown<br />
‘infection’ in a mushroom bed. Hawker (1959) did some developmental<br />
studies on Diehliomyces and concluded that <strong>the</strong> ascomata<br />
were not truly folded as in a typical member of <strong>the</strong><br />
<strong>Tuberales</strong>, and she supported a transfer <strong>to</strong> <strong>the</strong> Eurotiales. She<br />
found a completely irregular arrangement of <strong>the</strong> ascogenous<br />
hyphae and asci, even at very early stages of development.<br />
Currah (1985) excluded it from <strong>the</strong> Onygenales, where Benny &<br />
Kimbrough (1980) had accepted it.<br />
Excluded truffle taxa<br />
Amylocarpus Curr. 1859<br />
Type: Amylocarpus encephaloides.<br />
This monotypic genus has passive spore dispersal but develops<br />
on intertidal wood and, although originally included in<br />
<strong>the</strong> Tuberaceae, it cannot be considered a truffle in <strong>the</strong> sense of<br />
this paper. Its current position is unsettled (e.g. Landvik et al.<br />
1998). It is listed as Leotiomycetidae with unclear position in<br />
Kirk et al. (2001) and as Helotiales incertae sedis in Eriksson (2006a).<br />
General information<br />
For general information on truffles refer, for example, <strong>to</strong> North<br />
American Truffling Society (www.natruffling.org/) and e.g.<br />
Bucquet-Grenet & Dubarry (2001). A very extensive bibliography<br />
on <strong>the</strong> genus Tuber can be found in Ceruti et al. (2003).<br />
Also, Trappe & Maser (1977) and Trappe et al. (2001) should<br />
be consulted. Recently a very illustrative guide <strong>to</strong> Andalucian<br />
truffles directed at <strong>the</strong> general public has been published (Arroyo<br />
et al. 2005). Dannell (1996) published a useful popular review<br />
in Swedish.<br />
Discussion<br />
Phylogenetic relationships of truffles within Pezizales<br />
Within <strong>the</strong> last 13 y molecular phylogenetic studies have gradually<br />
confirmed and greatly expanded our knowledge on a repeated<br />
evolution of ascomyce<strong>to</strong>us truffles across Pezizales.<br />
The first study <strong>to</strong> address <strong>the</strong> controversial issue of <strong>the</strong> placement<br />
of Tuber was that of Landvik & Eriksson (1994a), who<br />
confirmed <strong>the</strong> placement within Pezizales, as predicted by<br />
Trappe (1979) and o<strong>the</strong>rs. Elaphomyces was erroneously indicated<br />
<strong>to</strong> be nested within Pezizales (Landvik & Eriksson<br />
1994a; but see Landvik & Eriksson 1994b), but was later shown<br />
<strong>to</strong> be closely related <strong>to</strong> Eurotiales and Onygenales (Landvik et al.<br />
1996). The early study by Landvik & Eriksson (1994b) showed<br />
that Glaziella, with <strong>the</strong> highly unusual ascomatal form, was<br />
nested within Pezizales. Attempts <strong>to</strong> find out <strong>the</strong> exact relationship<br />
of Glaziella have since been carried out (see Glaziellaceae<br />
above). The molecular study by O’Donnell et al. (1997)<br />
included a large number of truffles <strong>to</strong>ge<strong>the</strong>r with a large number<br />
of pezizalean epigeous taxa (from lineage B) and was <strong>the</strong><br />
first <strong>to</strong> discover multiple (at least five), independently derived,<br />
hypogeous clades within Pezizales. It resulted in new family<br />
assignments for several truffles and revealed a relationship<br />
between Tuberaceae and Helvellaceae. Percudani et al. (1999)<br />
focused on hypogeous Pezizales phylogeny and species<br />
thought <strong>to</strong> belong <strong>to</strong> <strong>the</strong> Balsamiaceae, Terfeziaceae, and Tuberaceae.<br />
Unfortunately <strong>the</strong>y included only few epigeous taxa,<br />
which resulted in Cazia, Mattirolomyces, Pachyphloeus, and Terfezia<br />
(Terfeziaceae) erroneously formed a monophyletic group<br />
within Pezizaceae. A study with a broader sampling of epigeous<br />
pezizaceous species followed (Norman & Egger 1999) that<br />
showed ‘Terfeziaceae’ are not monophyletic. The study of<br />
epigeous-hypogeous relationships within Pezizaceae was<br />
fur<strong>the</strong>r expanded (Hansen et al. 2001) and gave support for at<br />
least three independent origins of hypogeous forms within<br />
<strong>the</strong> family. Most recently, Perry et al. (2007) focusing on Pyronemataceae,<br />
with a large taxon sampling, suggested that <strong>the</strong> truffle<br />
form has arisen at least five times independently within<br />
that family. All of <strong>the</strong>se studies used regions from <strong>the</strong> nuclear<br />
ribosomal genes. One multi-locus study has emerged (Hansen<br />
et al. 2005) substantiating <strong>the</strong> evolution of truffles within Pezizaceae<br />
using combined analyses of LSU rDNA and protein-coding<br />
genes, RNA polymerase II (RPB2), and b-tubulin.<br />
Several fur<strong>the</strong>r papers dealing with <strong>the</strong> phylogeny of truffles<br />
(e.g. Diéz et al. 2002; Ferdman et al. 2005) have unfortunately<br />
only included truffles in <strong>the</strong> analyses, which have<br />
made it difficult <strong>to</strong> pinpoint epigeous relatives and fully<br />
understand <strong>the</strong>ir relationships and taxonomy. Vizzini (2003)<br />
gave <strong>the</strong> most recent review of ascomyce<strong>to</strong>us truffles.<br />
The 55 species of truffles included in <strong>the</strong> current review occur<br />
in 15 separate lineages within <strong>the</strong> Pezizales: in nine lineages<br />
within Pezizaceae (Fig 2), in three lineages within<br />
Morchellaceae–Discinaceae–Helvellaceae–Tuberaceae (Fig 3) and<br />
in three lineages within Pyronemataceae (Fig 4). The only strictly<br />
hypogeous family known is currently Tuberaceae. Table 2 gives<br />
an overview of recent classifications of pezizalean truffles and<br />
an up-<strong>to</strong>-date classification based on both molecular and<br />
morphological characters.<br />
Cy<strong>to</strong>logy<br />
The number of nuclei in mature ascospores within <strong>the</strong> Pezizales<br />
has long been considered a character of major importance<br />
in defining taxa (see e.g. Ber<strong>the</strong>t 1964; Korf 1973a,<br />
1973b and Zhang 1992a,b). It has been shown that <strong>the</strong><br />
hypogeous members of <strong>the</strong> Pezizales also tend <strong>to</strong> have <strong>the</strong><br />
same number of nuclei in <strong>the</strong> spores within a certain family<br />
or genus. Tuber is an exception, as <strong>the</strong> spores can have from<br />
one <strong>to</strong> 18 nuclei, although most species have four nuclei in<br />
each spore (Vizzini 2003). The known numbers are summarized<br />
in Table 3. Zhang (1992a) found Genea (two species),
1094 T. Læssøe, K. Hansen<br />
Table 2 – Different recent classification schemes of<br />
pezizalean truffles<br />
<strong>Tuberales</strong><br />
(Korf 1973a)<br />
Hypogeous<br />
Pezizales<br />
(Trappe 1979)<br />
Suggested<br />
classification of<br />
hypogeous Pezizales<br />
Elaphomycetaceae Pezizaceae Pezizaceae<br />
Elaphomyces Amylascus Amylascus<br />
Mycoclelandia Cazia<br />
(as Clelandia)<br />
Eremiomyces<br />
Hydnotryopsis Hydnobolites<br />
Peziza spp.<br />
Hydnotryopsis<br />
Tirmania<br />
Kalaharituber<br />
Mattirolomyces<br />
Terfeziaceae Terfeziaceae<br />
Mycoclelandia<br />
Carbomyces Choiromyces<br />
Pachyphloeus<br />
Delastria Delastria<br />
Peziza spp.<br />
Mukagomyces Hydnobolites<br />
Ruhlandiella<br />
Paradoxa Pachyphloeus<br />
Sphaerozone<br />
Picoa Terfezia<br />
Terfezia<br />
Terfezia<br />
Tirmania<br />
Tirmania<br />
Helvellaceae Helvellaceae<br />
Hydnotrya Balsamia<br />
Tuberaceae Dingleya Barssia<br />
Barssia<br />
Balsamia<br />
Fischerula Helvella astieri<br />
Caulocarpa<br />
Balsamiaceae Tuberaceae<br />
Choiromyces<br />
Balsamia Choiromyces<br />
Elderia<br />
Barssia Dingleya<br />
Fischerula<br />
Picoa Labyrinthomyces<br />
Lespiaultinia<br />
Paradoxa<br />
Labyrinthomyces Tuberaceae<br />
Reddelomyces<br />
Hydnobolites<br />
Paradoxa<br />
Tuber<br />
Hydnoplicata<br />
Tuber<br />
Hydnotrya<br />
Pachyphloeus<br />
Phyma<strong>to</strong>myces<br />
Piersonia<br />
Pro<strong>to</strong>genea<br />
Pseudobalsamia<br />
Stephensia<br />
Tuber<br />
Pyronemataceae<br />
Geopora cooperi<br />
Hydnocystis<br />
Morchellaceae/<br />
Discinaceae<br />
Gymnohydnotrya<br />
Hydnotrya<br />
Fischerula<br />
Leucangium<br />
Pyronemataceae<br />
Labyrinthomyces Genabea<br />
Paurocotylis<br />
Genea<br />
Petchiomyces<br />
Geopora cooperi<br />
Sphaerozone<br />
Gilkeya<br />
Stephensia<br />
Hydnocystis<br />
Paurocotylis<br />
Petchiomyces<br />
Geneaceae Geneaceae Phaeangium ¼ Picoa?<br />
Genea Genea Picoa<br />
Hydnocystis Genabea Sphaerosoma<br />
Petchiomyces Stephensia<br />
Glaziellaceae<br />
Glaziella<br />
Carbomycetaceae Carbomycetaceae<br />
Carbomyces Carbomyces<br />
The adopted classification (right column) is based on recent molecular<br />
phylogenies combined with morphological characters.<br />
Hydnobolites cerebriformis, Pachyphloeus citrinus, and Mattirolomyces<br />
terfezioides (as Terfezia), <strong>to</strong> be uni-nucleate. This<br />
led Zhang <strong>to</strong> propose <strong>the</strong> synonymy of Geneaceae with<br />
Pyronemataceae, and fur<strong>the</strong>rmore, restricted Terfeziaceae <strong>to</strong><br />
uninucleate taxa (now incorporated in <strong>the</strong> Pezizaceae). The Helvellaceae<br />
have been considered <strong>to</strong> be defined by tetra-nucleate<br />
spores, but it is now evident that this number is a plesiomorphic<br />
character (also present in Discinaceae and some taxa of<br />
Tuberaceae) and thus has very limited discriminative value.<br />
The placement of f.ex Hydnotrya (Trappe 1979) and Choiromyces<br />
(e.g. Pegler et al. 1993) in <strong>the</strong> Helvellaceae was argued along<br />
those lines. However, molecular phylogenetic analyses of<br />
SSU and LSU rDNA suggest that Hydnotrya belongs <strong>to</strong> Discinaceae<br />
and Choiromyces <strong>to</strong> Tuberaceae (O’Donnell et al. 1997)(Fig 3).<br />
Ecological aspects of <strong>the</strong> truffle syndrome<br />
Various evolutionary processes may be involved in <strong>the</strong> truffle<br />
syndrome, but <strong>the</strong> most generally accepted is <strong>the</strong> avoidance<br />
of desiccation (e.g. Thiers 1984). The high truffle diversity in<br />
arid areas favours this hypo<strong>the</strong>sis. Some truffles, like Tuber aestivum<br />
and T. melanosporum, clearly have an outer layer that renders<br />
protection, <strong>to</strong> both mechanical and desiccation stresses,<br />
but many o<strong>the</strong>rs have very delicate fruit bodies, often formed<br />
in <strong>the</strong> upper soil layers, where desiccation pressures can exist,<br />
although of a less harsh nature than above ground. Ano<strong>the</strong>r<br />
driving force could be protection against above-ground predation<br />
of immature ascomata. At maturity <strong>the</strong> production of pungent<br />
volatile compounds attracts preda<strong>to</strong>rs of a kind <strong>the</strong> truffles<br />
have co-evolved with, or at least adapted <strong>to</strong>, in order <strong>to</strong> facilitate<br />
spore dispersal. Pacioni et al. (1990) speculated on o<strong>the</strong>r functions<br />
of <strong>the</strong> compounds, including microbial control of <strong>the</strong> micro-rhizosphere.<br />
Spores of hypogeous fungi probably persist for<br />
longer in <strong>the</strong> soil than those of wind-dispersed relatives, which<br />
presumably is of importance in respect <strong>to</strong> life in a xeric environment<br />
and as ec<strong>to</strong>mycorrhiza formers (e.g. Miller et al. 1994).<br />
It is generally assumed that most hypogeous fungi, including<br />
those in <strong>the</strong> Pezizales, form ec<strong>to</strong>mycorrhiza. Direct proof of<br />
this has not been established in all cases, but circumstantial<br />
evidence clearly indicates <strong>the</strong> validity of this assumption<br />
(e.g. Pacioni & Comandini 1999; Montecchi & Sarasini 2000).<br />
Early on some of <strong>the</strong>se relationships were considered parasitic,<br />
e.g. those with Cistaceae (Singer 1961). Awameh &<br />
Alsheikh (1979) and Awameh et al. (1979) claimed that some<br />
Terfezia and Tirmania spp. form ec<strong>to</strong>mycorrhiza with Helian<strong>the</strong>mum,<br />
but Kovács et al. (2003) have pointed out some important<br />
morphological discrepancies compared <strong>to</strong> typical EM<br />
structures casting doubt on <strong>the</strong>se conclusions. Based on<br />
morphotyping and sequencing of ec<strong>to</strong>mycorrhizal root tips,<br />
Tedersoo et al. (2006) identified 33 species of Pezizales <strong>to</strong> be<br />
ec<strong>to</strong>mycorrhizal, including species of Genea, Geopora, Helvella,<br />
Hydnotrya, Pachyphloeus, Peziza, Sarcosphaera, and Tuber. They<br />
hypo<strong>the</strong>sized that <strong>the</strong> ec<strong>to</strong>mycorrhizal lifestyle is a precondition<br />
for <strong>the</strong> switch <strong>to</strong> hypogeous fruiting. Most well-known<br />
mycorrhizal trees would appear <strong>to</strong> be involved in associations<br />
with pezizalean truffles, including various members of <strong>the</strong><br />
Fagaceae, Betulaceae, Pinaceae, and Myrtaceae. It is generally<br />
assumed that truffles prefer warm, fairly dry climates and<br />
calcareous soils, but this may be slightly overstated due <strong>to</strong><br />
<strong>the</strong> emphasis of requirements for <strong>the</strong> edible Tuber species.<br />
Still, <strong>the</strong> overall species diversity appears <strong>to</strong> be highest in<br />
alkaline soils in warm temperate <strong>to</strong> subtropical climates.<br />
Desert areas around <strong>the</strong> world also have a special truffle
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1095<br />
Table 3 – A compilation of <strong>the</strong> known number of nuclei in mature ascospores in hypogeous Pezizales<br />
Taxon Nuclei/ascospore Reference<br />
Lineage A (Pezizaceae) 1 (<strong>to</strong> 4?)<br />
Hydnobolites cerebriformis 1 Zhang (1992a)<br />
Mattirolomyces terfezioides, M. tiffanyae 1 Zhang (1992a; Healy 2003)<br />
Muciturbo (¼ Ruhlandiella?) 1 Warcup & Talbot (1989)<br />
Pachyphloeus citrinus 1 Zhang (1992a)<br />
Picoa juniperi 4? Donadini (1986b)<br />
Lineage B (Discinaceae-Tuberaceae) 1–17<br />
Balsamia platyspora, B. vulgaris 4 Donadini (1986b)<br />
Barssia oregonensis 4 Kimbrough et al. (1996)<br />
Choiromyces gangliformis 4 Zhang & Minter (1989a)<br />
Gymnohydnotrya australiana 4 Zhang & Minter (1989b)<br />
Helvella astieri 4 Korf (1973b)<br />
Hydnotrya michaelis, H. tulasnei, H. cerebriformis 4 Ber<strong>the</strong>t (1982); Donadini (1986a); Zhang (1991b)<br />
Leucangium carthusianum 4þ Li (1997)<br />
Tuber rufum 1–2 Vizzini (2003)<br />
Tuber aestivum, T. brumale, T. excavatum,<br />
T. indicum, T. magnatum, T. mesentericum<br />
2–4 Vizzini (2003)<br />
Tuber maculatum 2–8 Vizzini (2003)<br />
Tuber borchii, T. puberulum (2–)4–17 Donadini (1987), Vizzini (2003)<br />
Tuber melanosporum 6–8 Parguey-Leduc et al. (1987a)<br />
Lineage C (Pyronemataceae) 1 (<strong>to</strong> 5?)<br />
Genea klotzii, G. sinensis, G. variabilis, G. verrucosa 1 Donadini (1986a); Zhang (1991a, 1992a)<br />
Geopora cooperi 1 Donadini (1987)<br />
Hydnocystis clausa, H. piligera 1 Donadini (1986a, 1987)<br />
Stephensia shanori 1 (<strong>to</strong> 5?) Uecker (1967)<br />
funga, notably including Terfezia and Tirmania species.<br />
Amongst pezizalean truffles only Paurocotylis is at present considered<br />
<strong>to</strong> be saprotrophic (Castellano et al. 2004) or suspected<br />
<strong>to</strong> be so (Dennis 1975).<br />
Conclusion<br />
In conclusion, <strong>the</strong> trend that started with abandoning <strong>the</strong><br />
<strong>Tuberales</strong>, now robustly confirmed, has continued at <strong>the</strong><br />
family level where ‘pure’ hypogeous monophyla have been reduced<br />
<strong>to</strong> a single taxon, <strong>the</strong> Tuberaceae. At least 15 independent<br />
origins of hypogeous forms within <strong>the</strong> Pezizales are<br />
supported by <strong>the</strong> LSU rDNA gene trees. Different types of<br />
hypogeous ascomata forms, infolded or chambered<br />
ptyco<strong>the</strong>cia, solid ptyco<strong>the</strong>cia and stereo<strong>the</strong>cia, appear <strong>to</strong><br />
have evolved multiple times independently with <strong>the</strong> linages<br />
A and B of Pezizales; within lineage C only infolded or chambered<br />
ptyco<strong>the</strong>cia are present. No clear picture is shown by<br />
<strong>the</strong> LSU phylogenies of <strong>the</strong> hypo<strong>the</strong>sis that evolution from<br />
an epigeous, actively dispersed form (apo<strong>the</strong>cial) <strong>to</strong> a hypogeous,<br />
passively dispersed form (stereo<strong>the</strong>cial), proceeds<br />
through an intermediate semi-immersed form. Never<strong>the</strong>less,<br />
several smaller clades include such forms and future studies,<br />
including additional molecular data and taxa, providing<br />
a more robust phylogeny, may likely show such a progression.<br />
Much has been learnt on truffle biology, taxonomy, and phylogeny<br />
as <strong>the</strong> <strong>Tuberales</strong> were abandoned as an independent<br />
order but all three fields are still very active research areas<br />
where many exciting results will be forthcoming in <strong>the</strong> near<br />
future.<br />
Acknowledgements<br />
Thanks <strong>to</strong> Jens H. Petersen for providing and editing pho<strong>to</strong>graphs,<br />
and <strong>to</strong> Christian Lange, Jan Vesterholt, Johan Nitare,<br />
Juan San<strong>to</strong>s, and Manuel Tabarés for allowing us <strong>to</strong> use <strong>the</strong>ir<br />
pictures. Jim Trappe is thanked for help with references, advice<br />
on truffle matters in general and for supplying many of<br />
<strong>the</strong> specimens used by K.H. for molecular work. Rosanne<br />
Healy is thanked for providing specimens of Pachyphloeus.<br />
Donald H. Pfister is thanked for discussions and support of<br />
this work. The suggestions from two anonymous reviewers<br />
are greatfully acknowledged. The research contributed by<br />
K.H. was financially supported by an NSF grant <strong>to</strong> Donald<br />
H. Pfister and K.H. (DEB-0315940). T.L. thanks David Hawksworth<br />
for initiating this review, and he and Scott LaGreca<br />
are thanked for hosting ‘The New Bottles for Old Wine: fruit<br />
body types, phylogeny and classication’ BMS annual conservation<br />
and taxonomy meeting.<br />
references<br />
Abbott SP, Currah RS, 1997. The Helvellaceae: systematic revision<br />
and occurrence in nor<strong>the</strong>rn and northwestern North America.<br />
Mycotaxon 62: 1–125.<br />
Alsheikh AM, Trappe JM, 1983a. Desert truffles: <strong>the</strong> genus<br />
Tirmania. Transactions of <strong>the</strong> British Mycological Society 81: 83–90.<br />
Alsheikh M, Trappe JM, 1983b. Taxonomy of Phaeangium lefebvrei,<br />
a desert truffle eaten by birds. Canadian Journal of Botany 61:<br />
1919–1925.
1096 T. Læssøe, K. Hansen<br />
Alvarez IF, Parlade J, Trappe JM, 1993(1992). Loculotuber gennadii<br />
gen. et comb. nov. and Tuber multimaculatum sp. nov. Mycologia<br />
84: 926–929.<br />
Arroyo BM, Gómes Fernández J, Pulido Calmaestra E, 2005. Tesoros<br />
de Nuestros Montes. Trufas de Andalucía. Consejería de Medio<br />
Ambiente, Córdoba.<br />
Awameh MS, Alsheikh AM, 1979. Labora<strong>to</strong>ry and field study of<br />
four kinds of truffle (kamah), Terfezia and Tirmania species, for<br />
cultivation. Mushroom Science 10: 507–517.<br />
Awameh MS, Alsheikh AM, Al-Ghawas S, 1979. Mycorrhizal syn<strong>the</strong>sis<br />
between Helian<strong>the</strong>mum ledifolium, H. salicifolium and four<br />
species of <strong>the</strong> genera Terfezia and Tirmania using ascospores<br />
and mycelial cultures obtained from ascospore germination.<br />
Fourth North American Conference on Mycorrhizae, Colorado State<br />
University, Fort Collins.<br />
Bea<strong>to</strong>n G, Weste G, 1977. The genus Labyrinthomyces. Transactions<br />
of <strong>the</strong> British Mycological Society 69: 243–247.<br />
Bea<strong>to</strong>n G, Weste G, 1978. The genus Sphaerozone. Transactions of <strong>the</strong><br />
British Mycological Society 71: 164–167.<br />
Bea<strong>to</strong>n G, Weste G, 1982. Australian hypogeous ascomycetes.<br />
Transactions of <strong>the</strong> British Mycological Society 79: 455–468.<br />
Benny GL, Kimbrough JW, 1980. A synopsis of <strong>the</strong> orders and<br />
families of <strong>the</strong> Plec<strong>to</strong>mycetes with keys <strong>to</strong> genera. Mycotaxon 12:<br />
1–91.<br />
Ber<strong>the</strong>t P, 1963. Le nombre des noyaux dans la spore et son intérêt<br />
pour la systématique des discomycètes operculés. Compte<br />
Rendu Hebdomadaire des Séances de l‘Academie des Sciences, Paris<br />
256: 5185–5186.<br />
Ber<strong>the</strong>t P, 1964. Essai biotaxinomique sur les discomycète. PhD<br />
<strong>the</strong>sis. Faculté des Sciences de l’Université de Lyon.<br />
Ber<strong>the</strong>t P, 1982. Sur la position taxonomique d’Hydnotrya michaelis<br />
(Fischer) Trappe (¼Geoporella michaelis (Fischer) Soehner)<br />
(Ascomycètes). Bulletin trimestriel de la Société Mycologique de<br />
France 98: 75–79.<br />
Blaschke H, 1987. Vorkommen und Charakterisierung der Ek<strong>to</strong>mykorrhizaassoziation<br />
Tuber puberulum mit Picea abies. zeitschrift<br />
für Mykologie 53: 283–288.<br />
Bougher NL, Lebel T, 2001. Sequestrate (truffle-like) fungi of<br />
Australia and New Zealand. Australian Systematic Botany 14:<br />
439–484.<br />
van Brummelen J, 1994. Problems in <strong>the</strong> systematics of Pezizales.<br />
In: Hawksworth DL (ed.), Ascomycete Systematics: problems<br />
and perspectives in <strong>the</strong> nineties. Plenum Press, New York, pp.<br />
303–309.<br />
Bucquet-Grenet S, Dubarry F, 2001. L’ABCdaire de la Truffe. Flammarion,<br />
Paris, (English version, The Little Book of <strong>Truffle</strong>s).<br />
Burdsall jr HH, 1965. Operculate asci and puffing of ascospores in<br />
Geopora (<strong>Tuberales</strong>). Mycologia 57: 485–488.<br />
Burdsall jr HH, 1968. A revision of <strong>the</strong> genus Hydnocystis<br />
(<strong>Tuberales</strong>) and of <strong>the</strong> hypogeous species of Geopora (Pezizales).<br />
Mycologia 60: 496–525.<br />
Castellano MA, Trappe JM, Luoma DL, 2004. Sequestrate fungi.<br />
In: Mueller GM, Bills GF, Foster MS (eds), Biodiversity of Fungi.<br />
Inven<strong>to</strong>ry and Moni<strong>to</strong>ring Methods. Elsevier, Amsterdam, pp.<br />
197–213.<br />
Castellano MA, Trappe JM, Maser Z, Maser C, 1989. Key <strong>to</strong> Spores of<br />
<strong>the</strong> Genera of Hypogeous Fungi of North Temperate Forests with<br />
Special Reference <strong>to</strong> Animal Mycophagy. Mad River Press,<br />
Eureka.<br />
Ceruti A, Fontana A, Nosenzo C, 2003. Le Specie Europee del Genere<br />
Tuber: una revisione s<strong>to</strong>rica. Museo Regionale di Scienze Naturali,<br />
Torino.<br />
Chevalier G, Frochot H, 1997. La Truffe de Bourgogne. Levallois-<br />
Perret.<br />
Claridge AW, Cork SJ, Trappe JM, 2000. Diversity and habitat relationships<br />
of hypogeous fungi. I. Study design, sampling<br />
techniques and general survey results. Biodiversity and Conservation<br />
9: 151–173.<br />
Claridge AW, May TW, 1994. Mycophagy among Australian<br />
mammals. Australian Journal of Ecology 19: 251–275.<br />
Claus R, Hoppen HO, Karg H, 1981. The secret of truffles: a steroidal<br />
pheromone? Experientia 37: 1178–1179.<br />
Currah RS, 1985. Taxonomy of <strong>the</strong> Onygenales: Arthrodermataceae,<br />
Gymnoascaceae, Myxotrichaceae and Onygenaceae. Mycotaxon 24:<br />
1–216.<br />
Dannell E, 1996. Tryfflar i Sverige och u<strong>to</strong>mlands [<strong>Truffle</strong>s and<br />
false truffles in Sweden and abroad]. Svensk Botanisk Tidskrift<br />
90: 215–230.<br />
Dennis RWG, 1975. New or interesting British microfungi, III. Kew<br />
Bulletin 30: 345–365.<br />
De Vi<strong>to</strong> A, 2003. Stephensia colomboi sp. nov. Una nuova specie<br />
delle Alpi Orobiche. Rivista di Micologia, Bollettino dell’ Associazione<br />
Micologica Bresasola 36: 221–225.<br />
Diehl WW, Lambert EB, 1930. A new truffle in beds of cultivated<br />
mushrooms. Mycologia 22: 223–226 pl. 27.<br />
Diéz J, Manjón JL, Martin F, 2002. Molecular phylogeny of<br />
<strong>the</strong> mycorrhizal desert truffles (Terfezia and Tirmania),<br />
host specificity and edaphic <strong>to</strong>lerance. Mycologia 94: 247–259.<br />
Dissing H, Korf RP, 1980. Preliminary studies in <strong>the</strong> genera Ruhlandiella,<br />
Sphaerosoma, and Sphaerozone (order Pezizales). Mycotaxon<br />
12: 287–306.<br />
Dissing H, Schumacher T, 1994. Pezizales. In: Hawksworth DL (ed.),<br />
Ascomycete Systematics: problems and perspectives in <strong>the</strong> nineties.<br />
Plenum Press, New York, pp. 397–401.<br />
Donadini JC, 1986a. Hydnotrya tulasnei (Berk.) Berk. & Br. His<strong>to</strong>logie,<br />
cy<strong>to</strong>logy, scanning. Sa place dans les Helvellacées. Documents<br />
Mycologique 17: 19–33.<br />
Donadini JC, 1986b. Les Balsaminiacées son des Helvellacées: cy<strong>to</strong>logy<br />
et scanning de Balsamia vulgaris Vitt. et de Balsamia platyspora<br />
Berk. et Br. Bulletin trimestriel de la Société de Mycologique de<br />
France 102: 373–387.<br />
Donadini JC, 1987. Pezizales et <strong>Tuberales</strong> (2). Le genre Tuber<br />
(T. borchii Vitt. et T. puberulum Berk. & Broome). Cy<strong>to</strong>logie des<br />
spores, paraphyses et poils par coloration microscopie électronique<br />
(Tuber melanosporum). Documents Mycologique 18:<br />
47–60.<br />
Eckblad F-E, 1968. The genera of <strong>the</strong> operculate Discomycetes. A reevaluation<br />
of <strong>the</strong>ir taxonomy, phylogeny and nomenclature.<br />
Nytt Magasin for Botanikk 15: 1–191.<br />
Eggerling TW, 2004. Paurocotylis pila. Field Mycology 5: 41–42.<br />
Eriksson OE, 1982. Outline of <strong>the</strong> ascomycetes d 1982. Mycotaxon<br />
15: 203–248.<br />
Eriksson OE, 2006a. Outline of Ascomycota d 2006. Myconet 12:<br />
1–82.<br />
Eriksson OE, 2006b. Notes on ascomycete systematics. 4361.<br />
Pezizales. Myconet 12: 83–101.<br />
Eriksson OE, Winka K, 1998. Families and higher taxa of Ascomycota.<br />
Myconet 1: 17–24.<br />
Ferdman Y, Aviram S, Roth-Bejerano N, Trappe JM, Kagan-Zur V,<br />
2005. Phylogenetic studies of Terfezia pfeilii and Choiromyces<br />
echinulatus (Pezizales) support new genera for sou<strong>the</strong>rn African<br />
truffles: Kalaharituber and Eremiomyces. Mycological Research<br />
109: 237–245.<br />
Fischer E, 1897. Tuberineae, Plectascineae. In: Engler A, Prantl K<br />
(eds), Die natürlichen Pflanzenfamilien. Verlag von Wilhelm<br />
Engelmann, Leipzig, pp. 278–320.<br />
Fischer E, 1938. Tuberineae. In: Engler A, Prantl K (eds). Die natürlichen<br />
Pflanzenfamilien. Part 5b, 2nd edn, Vol. III, Verlag von<br />
Wilhelm Engelmann, Leipzig.<br />
Fogel R, States J, 2002. Materials for a hypogeous mycoflora of<br />
<strong>the</strong> Great Basin and adjacent cordilleras of <strong>the</strong> Western<br />
United States. VIII: Pachyphloeus lateritius sp. nov. and Cazia<br />
quercicola sp. nov. (Ascomycota, Pezizales). Mycotaxon 81:<br />
83–89.<br />
Fogel R, States J, 2003. Materials for a hypogeous mycoflora of <strong>the</strong><br />
Great Basin and adjacent cordilleras of <strong>the</strong> Western United
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1097<br />
States. IX. A new name for Peziza quercicola Fogel & States<br />
(Ascomycota, Pezizales). Mycotaxon 88: 155–156.<br />
Fogel R, Trappe JM, 1978. Fungus consumption (mycophagy) by<br />
small animals. Northwest Science 52: 1–31.<br />
Fontana A, Giovannetti G, 1987. The anamorph of Stephensia<br />
bombycina. Mycotaxon 29: 37–44.<br />
Fries E, 1821–1832. Systema mycologicum I–III & Elenchus Fungorum<br />
I–II. Lund/Greifswald.<br />
Galán R, Moreno G, 1998. Ruhlandiella beroliensis, an exotic species<br />
in Europe. Mycotaxon 68: 265–271.<br />
Gamundi I, 1976 [1975]. Acerca de los géneros Boudiera Cooke y<br />
Sphaerosoma Klotsch (Fungi, Pezizales). Sydowia 28: 339–352.<br />
Gilkey HM, 1939. <strong>Tuberales</strong> of North America. Oregon State Monographs.<br />
Studies in Botany 1: 1–63.<br />
Gilkey HM, 1954. <strong>Tuberales</strong>. North American Flora 2 (1): 1–36.<br />
Gilkey HM, 1955 [1954]. Taxonomic notes on <strong>Tuberales</strong>. Mycologia<br />
46: 783–793.<br />
Gutierrez A, Morte A, Honrubia M, 2003. Morphological characterization<br />
of <strong>the</strong> mycorrhiza formed by Helian<strong>the</strong>mum almeriense<br />
Pau with Terfezia claveryi Chatin and Picoa lefebvrei (Pat.)<br />
Maire. Mycorrhiza 13: 299–307.<br />
Hansen K, 2000. Muciturbo Talbot. In: Eriksson O (ed.), Notes on<br />
ascomycete systematics nos 2940–3127(3015). Myconet 5: 17–18.<br />
Hansen K, Læssøe T, Pfister DH, 2001. Phylogenetics of <strong>the</strong><br />
Pezizaceae, with an emphasis on Peziza. Mycologia 93: 958–990.<br />
Hansen K, LoBuglio KF, Pfister DH, 2005. Evolutionary relationships<br />
of <strong>the</strong> cup-fungus genus Peziza and Pezizaceae inferred<br />
from multiple nuclear genes: RPB2, b-tubulin, and LSU rDNA.<br />
Molecular Phylogenetics and Evolution 36: 1–23.<br />
Hansen K, Perry BA, Pfister DH, 2006 [2005]. Phylogenetic origins<br />
of two cleis<strong>to</strong><strong>the</strong>cial fungi, Orbicula parietina and Lasiobolidium<br />
orbiculoides, within <strong>the</strong> operculate discomycetes. Mycologia 97:<br />
1023–1033.<br />
Hansen K, Pfister DH, 2007. Systematics of <strong>the</strong> Pezizomycetes d <strong>the</strong><br />
operculate discomycetes. Mycologia 98: 1031–1041.<br />
Hansen K, Trappe JA, 2002. Terfeziaceae E. Fisch. In: Eriksson OE,<br />
Baral HO, Currah RS, Hansen K, Kurtzman CP, Laessøe T,<br />
Rambold G (eds), Notes on ascomycete systematics nos. 3403-<br />
3579(3471). Myconet 8: 33–34.<br />
Hansen L, Knudsen H (eds), 2000. Nordic Macromycetes 1. Ascomycetes.<br />
Nordsvamp, Copenhagen.<br />
Harring<strong>to</strong>n FA, Pfister DH, Potter D, Donoghue MJ, 1999. Phylogenetic<br />
studies within <strong>the</strong> Pezizales. I. 18S rRNA sequence data<br />
and classification. Mycologia 91: 41–50.<br />
Hawker LE, 1954. British hypogeous fungi. Philosophical Transactions<br />
of <strong>the</strong> Royal Society of London. Series B, Biological Sciences 237:<br />
429–546.<br />
Hawker LE, 1959. The development of <strong>the</strong> fruit-body of Diehliomyces<br />
microsporus (Diehl and Lambert) Gilkey (syn. Pseudobalsamia<br />
microspora Diehl and Lambert). Transactions of <strong>the</strong><br />
Botanical Society of Edinburgh 38: 71–75.<br />
Hawksworth DL, Sut<strong>to</strong>n BC, Ainsworth GC (eds), 1983. Ainsworth &<br />
Bisby’s Dictionary of <strong>the</strong> Fungi, 7th edn. Commonwealth Mycological<br />
Institute, Kew.<br />
He XY, Li HM, Wang Y, 2004. Tuber zhongdianense sp. nov. from<br />
China. Mycotaxon 90: 213–216.<br />
Healy RA, 2003. Mattirolomyces tiffanyae, a new truffle from Iowa,<br />
with ultrastructural evidence for its classification in <strong>the</strong><br />
Pezizaceae. Mycologia 95: 765–772.<br />
de Hoog GS, Göttlich E, Platas G, Genilloud, Leotta G, van<br />
Brummelen J, 2005. Evolution, taxonomy and ecology of <strong>the</strong><br />
genus Thelebolus in Antarctica. Studies in Mycology 51: 33–76.<br />
Huelsenbeck JP, Ronquist F, 2001. MRBAYES: Bayesian inference<br />
of phylogeny. Bioinformatics 17: 754–755.<br />
Janex-Favre MC, Parguey-Leduc A, 1985. Les asques et les ascospores<br />
du Terfezia claveryi Ch. (Tubérales). Cryp<strong>to</strong>gamie. Mycologie 6:87–99.<br />
Janex-Favre MC, Parguey-Leduc A, 2002. Particularités des ascocarpes<br />
et de l’hyménium des truffes (Ascomycètes). I.<br />
Développement et structure des ascocarpes. Cryp<strong>to</strong>gamie. Mycologie<br />
23: 103–128.<br />
Janex-Favre MC, Parguey-Leduc A, 2003. Particularités des ascocarpes<br />
et de l’hymenium des truffes (Ascomycetes). II. Organisation<br />
de l’hymenium det asques. Bulletin de la Société<br />
Mycologique de France 119: 31–59.<br />
Janex-Favre MC, Parguey-Leduc A, Riousset L, 1988. L’ascocarpe<br />
hypogé d’une terfez française (Terfezia lep<strong>to</strong>derma Tul., Tubérales,<br />
Discomycètes). Bulletin trimestriel de la Société de Mycologique<br />
de France 104: 145–178.<br />
Kimbrough JW, 1994. Septal ultrastructure and ascomycete systematics.<br />
In: Hawksworth DL (ed.), Ascomycete Systematics:<br />
problems and perspectives in <strong>the</strong> nineties. Plenum Press, New<br />
York, pp. 127–141.<br />
Kimbrough JW, Li LT, Wu CG, 1996. Ultrastructural evidence for<br />
<strong>the</strong> placement of <strong>the</strong> truffle Barssia in <strong>the</strong> Helvellaceae (Pezizales).<br />
Mycologia 88: 38–46.<br />
Kimbrough JW, Wu C-G, Gibson JL, 1991. Ultrastructural evidence<br />
for a phylogenetic linkage of <strong>the</strong> truffle genus Hydnobolites <strong>to</strong><br />
<strong>the</strong> Pezizaceae (Pezizales, Ascomycetes). Botanical Gazette 152:<br />
408–420.<br />
Kirk PM, Cannon PF, David JC, Stalpers JA (eds), 2001.<br />
Ainsworth & Bisby’s Dictionary of <strong>the</strong> Fungi. CABI Publishing,<br />
Wallingford.<br />
Kishino H, Hasegawa M, 1989. Evaluation of <strong>the</strong> maximum likelihood<br />
estimate of <strong>the</strong> evolutionary tree <strong>to</strong>pologies from DNA<br />
sequence data, and <strong>the</strong> branching order in Hominoidea. Journal<br />
of Molecular Evolution 29: 170–179.<br />
Knapp A, 1950. Die europäischen Hypogaeen-Gattungen und ihre<br />
Gattungstypen. Schweizerische Zeitschrift für Pilzkunde 28: 29–42<br />
101–118, 153–179.<br />
Knapp A, 1951. Die europäischen Hypogaeen-Gattungen und ihre<br />
Gattungstypen. Schweizerische Zeitschrift für Pilzkunde 29: 65–92<br />
133–150.<br />
Knapp A, 1952. Die europäischen Hypogaeen-Gattungen und ihre<br />
Gattungstypen. Schlussbetrachtung. Schweizerische Zeitschrift<br />
für Pilzkunde 30: 33–43.<br />
Korf RP, 1972. Synoptic key <strong>to</strong> <strong>the</strong> genera of <strong>the</strong> Pezizales. Mycologia<br />
64: 937–994.<br />
Korf RP, 1973a. Discomycetes and <strong>Tuberales</strong>. In: Ainsworth GC,<br />
Sparrow FK, Sussman AS (eds), The Fungi: an advanced treatise,<br />
Vol. IVA. Academic Press, New York, pp. 249–319.<br />
Korf RP, 1973b. Sparassoid ascomata in Pezizales and <strong>Tuberales</strong>.<br />
Reper<strong>to</strong>rium Tot<strong>to</strong>ri Mycological Institute 10: 389–403.<br />
Kovács GM, Jakucs E, 2006. Morphological and molecular<br />
comparison of white truffle ec<strong>to</strong>mycorrhizae. Mycorrhiza 16:<br />
567–574.<br />
Kovács GM, Jakucs E, Bagi I, 2007. Identification of host plants<br />
and description of sclerotia of <strong>the</strong> truffle Mattirolomyces terfezioides.<br />
Mycological Progress 6(1): 19–26, doi: 10.1007/s11557-<br />
006-0520-y.<br />
Kovács GM, Vágvölgyi C, Oberwinkler F, 2003. In vitro interaction<br />
of <strong>the</strong> truffle Terfezia terfezioides with Robinia pseudoacacia and<br />
Helian<strong>the</strong>mum ovatum. Folia Microbiologica 48: 369–378.<br />
Landvik S, 1996. Neolecta, a fruit-body-producing genus of <strong>the</strong><br />
basal ascomycetes, as shown by SSU and LSU rDNA sequences.<br />
Mycological Research 100: 199–202.<br />
Landvik S, Egger KN, Schumacher T, 1997. Towards a subordinal<br />
classification of <strong>the</strong> Pezizales (Ascomycota): phylogenetic analyses<br />
of SSU rDNA sequences. Nordic Journal of Botany 17: 403–418.<br />
Landvik S, Eriksson OE, 1994a. Relationships of Tuber, Elaphomyces<br />
and Cyttaria (Ascomycotina), inferred from 18S rDNA<br />
studies. In: Hawksworth DL (ed.), Ascomycete Systematics:<br />
problems and perspectives in <strong>the</strong> nineties. Plenum Press, New<br />
York, pp. 225–231.<br />
Landvik S, Eriksson OE, 1994b. Relationship of <strong>the</strong> genus Glaziella<br />
(Ascomycota) inferred from 18S rDNA sequences. Systema Ascomycetum<br />
13: 13–23.
1098 T. Læssøe, K. Hansen<br />
Landvik S, Kristiansen R, Schumacher T, 1998. Phylogenetic and<br />
structural studies in <strong>the</strong> Thelebolaceae (Ascomycota). Mycoscience<br />
39: 49–56.<br />
Landvik S, Shailer NFJ, Eriksson OE, 1996. SSU rDNA sequence<br />
support for a close relationship between <strong>the</strong> Elaphomycetales<br />
and <strong>the</strong> Eurotiales and Onygenales. Mycoscience 37:<br />
237–241.<br />
Lange M, 1956. Danish hypogeous macromycetes. Dansk Botanisk<br />
Arkiv 16: 1–84.<br />
Lawrynowicz M, 1988. Workowce (Ascomycetes), Jeleniakowe<br />
(Elaphomycetales), Truflowe (<strong>Tuberales</strong>). In: Grzyby (Mycota) Vol 18.<br />
PanstwoweWydawnictwo Naukowe, Warszawa-Kraków.<br />
Lawrynowicz M, 1991 [1989–90]. Chorology of European<br />
hypogeous ascomycetes. II. <strong>Tuberales</strong>. Acta Mycologici 26:<br />
7–75.<br />
Li L-T, 1997. Ultrastructural studies of Leucangium carthusianum<br />
(hypogeous Pezizales). International Journal of Plant Sciences 158:<br />
189–197.<br />
Li L-T, Kimbrough JW, 1994. Ultrastructural evidence for a relationship<br />
of <strong>the</strong> truffle genus Genea <strong>to</strong> Otideaceae (Pezizales).<br />
International Journal of Plant Sciences 155: 235–243.<br />
Li L-T, Kimbrough JW, 1995. Septal ultrastructure in three species<br />
of Tuber (hypogeous Pezizales). International Journal of Plant<br />
Sciences 156: 849–856.<br />
Maire RCJE, 1906. Notes mycologiques. Annales Mycologici 4: 329–<br />
335 1 fig.<br />
Malençon G, 1938. Les truffes européennes. His<strong>to</strong>rique, morphogénie,<br />
organographie, classification, culture. Revue Mycologique<br />
3 ((N.S.) Méacutem 1): 1–92.<br />
Malençon G, 1973. Champignons hypogés du nord de l’Afrique. I.<br />
Ascomycétes. Persoonia 7: 261–288.<br />
Marasas WFO, Trappe JM, 1973. Notes on sou<strong>the</strong>rn African<br />
<strong>Tuberales</strong>. Bothalia 11: 139–141.<br />
Marin AB, Libbey LM, Morgan ME, 1984. <strong>Truffle</strong>s: on <strong>the</strong> scent of<br />
a buried treasure. Mclilvainea 6: 34–38.<br />
Maser C, Trappe JM, Nussbaum RA, 1978. Fungal–small mammal<br />
interrelationships with emphasis on Oregon coniferous forests.<br />
Ecology 59: 799–809.<br />
Mattirolo O, 1928. Secondo elenco dei ‘funghi ipogaei’ raccolti<br />
nelle foreste di Vallombrosa (1900–1926). Nuovo Giornale Botanico<br />
Italiano 34: 1343–1358.<br />
Mello A, Murat C, Vizzini A, Gavazza V, Bonfante P, 2005. Tuber<br />
magnatum Pico, a species of limited geographical distribution:<br />
its genetic diversity inside and outside a truffle ground. Environmental<br />
Microbiology 7: 55–65.<br />
Mello A, Vizzini A, Longa<strong>to</strong> S, Rollo F, Bonfante P, Trappe JM, 2000.<br />
Tuber borchii versus Tuber maculatum: neotype studies and DNA<br />
analyses. Mycologia 92: 326–331.<br />
Miller SL, Torres P, McClean TM, 1994. Persistence of basidiospores<br />
and sclerotia of ec<strong>to</strong>mycorrhizal fungi and Morchella in<br />
soil. Mycologia 86: 89–95.<br />
Montecchi A, Lazzari G, 1993. Atlante Fo<strong>to</strong>grafico di Funghi Ipogei.<br />
Associazione Micologica Bresadola, Tren<strong>to</strong>.<br />
Montecchi A, Sarasini M, 2000. Funghi Ipogei d’Europa. Associazione<br />
Micologica Bresadola, Fondazione Centro Studi Micologici,<br />
Tren<strong>to</strong>.<br />
Moreno G, Déz J, Manjón JL, 2000. Picoa lefebvrei and Tirmania nivea,<br />
two rare hypogeous fungi from Spain. Mycological Research 104:<br />
378–381.<br />
Nannfeldt JA, 1946. En ny svensk hypogé, tryffeln Geopora schackii<br />
P. Henn [A new Swedish hypogeous fungus, Geopora schackii<br />
P. Henn.]. Friesia 3: 177–188.<br />
Norman JE, Egger KN, 1999. Molecular phylogenetic analysis of<br />
Peziza and related genera. Mycologia 91: 820–829.<br />
Nylander JAA, 2004. MrModeltest 2.2 Program distributed by <strong>the</strong><br />
author. Evolutionary Biology Centre, Uppsala University.<br />
O’Donnell K, Cigelnik E, Weber NS, Trappe JM, 1997. Phylogenetic<br />
relationships among ascomyce<strong>to</strong>us truffles and <strong>the</strong> true and<br />
false morels inferred from 18S and 28S ribosomal DNA<br />
sequence analysis. Mycologia 89: 48–65.<br />
Pacioni G, Bellina-Agostinone C, D’An<strong>to</strong>nio M, 1990. Odour<br />
composition of <strong>the</strong> Tuber melanosporum complex. Mycological<br />
Research 94: 201–204.<br />
Pacioni G, Comandini O, 1999. Tuber. In: Cairney JWG,<br />
Chambers SM (eds), Ec<strong>to</strong>mycorrhizal Fungi. Key Genera in Profile.<br />
Springer Verlag, Berlin, pp. 163–186.<br />
Palfner G, Agerer R, 1998a. Balsamia alba Harkness þ Pinus jeffreyi<br />
Grev. & Balf. Descriptions of Ec<strong>to</strong>mycorrhizae 3: 1–6.<br />
Palfner G, Agerer R, 1998b. Leucangium carthusianum (Tul.) Paol.<br />
(¼ Picoa carthusiana Tul. & Tul.) þ Pseudotsuga menziesii (Mirb.)<br />
Franco. Descriptions of Ec<strong>to</strong>mycorrhizae 3: 37–42.<br />
Parguey-Leduc A, Janex-Favre MC, Montant C, 1987a. Formation<br />
et evolution des ascospores de Tuber melanosporum (Truffe<br />
noire du Périgord, Discomycètes). Canadian Journal of Botany 65:<br />
1491–1503.<br />
Parguey-Leduc A, Janex-Favre MC, Montant C, 1990. L’appareil<br />
sporophytique et les asques du Tuber melanosporum Vitt.<br />
(Truffe noire du Périgord, Discomycètes). Cryp<strong>to</strong>gamie Mycologie<br />
11: 47–68.<br />
Parguey-Leduc A, Montant C, Kulifaj M, 1987b. Morphologie et<br />
structure de l’ascocarpe adulte du Tuber melanosporum Vitt.<br />
(Truffe noire du Périgord, Discomycetes). Cryp<strong>to</strong>gamie. Mycologie<br />
8: 173–202.<br />
Pa<strong>to</strong>uillard N, 1903. Note sur le genre Paurocotylis Berk. Bulletin de<br />
la Société de Mycologique de France 19: 339–341.<br />
Pegler DN, Spooner BM, Young TWK, 1993. British <strong>Truffle</strong>s.<br />
A Revision of British Hypogeous Fungi. Royal Botanic Gardens,<br />
Kew.<br />
Percudani R, Trevisi A, Zambonelli A, Ot<strong>to</strong>nello S, 1999. Molecular<br />
phylogeny of truffles (Pezizales: Terfeziaceae, Tuberaceae) derived<br />
from nuclear rDNA sequence analysis. Molecular Phylogenetics<br />
and Evolution 13: 169–180.<br />
Perry BA, Hansen K, Pfister DH, 2007. A phylogenetic overview of<br />
<strong>the</strong> family Pyronemataceae (Ascomycota, Pezizales). Mycological<br />
Research 111: 549–571. doi: 10.1016/j.mycres.2007.03.014.<br />
Pfister D, 1984. Genea–Jafneadelphus d a tuberalean–pezizalean<br />
connection. Mycologia 76: 170–172.<br />
Rauscher T, Agerer R, Chevalier G, 1995. Ek<strong>to</strong>mykorrhizen<br />
von Tuber melanosporum, Tuber mesentericum und Tuber<br />
rufum (<strong>Tuberales</strong>) an Corylus avellana. Nova Hedwigia 61:<br />
281–322.<br />
Roux C, Sejalon-Delmas N, Martins M, Parguey-Leduc A,<br />
Dargent R, Becard G, 1999. Phylogenetic relationships between<br />
European and Chinese truffles based on parsimony and<br />
distance analysis of ITS sequences. FEMS Microbiology Letters<br />
180: 147–155.<br />
Senn-Irlet B, Aeberhard H, 2005. Der Pilz des Monats (5). Hydnocystis<br />
piligera Tulasne et C. Tulasne 1844. Schweizerische Zeitschrift<br />
für Pilzkunde 83: 98–103.<br />
Shimodaira H, Hasegawa M, 1999. Multiple comparisons of<br />
log-likelihoods with applications <strong>to</strong> phylogenetic inference.<br />
Molecular Biology and Evolution 16: 1114–1116.<br />
Singer R, 1961. Mushrooms and <strong>Truffle</strong>s. Botany, Cultivation, and<br />
Utilization. Interscience Publications, London.<br />
Smith ME, Trappe JM, Rizzo DM, 2006. Genea, Genabea and Gilkeya<br />
gen. nov.: ascomata and ec<strong>to</strong>mycorrhiza formation in a<br />
Quercus woodland. Mycologia 98: 699–716.<br />
Swofford DL, 2002. PAUP*. Phylogenetic analysis using parsimony<br />
(*and o<strong>the</strong>r methods). Version 4. Sinauer Associates, Sunderland,<br />
MA.<br />
Szemere L, 1965. Die Unterirdischen Pilze des Karpatenbeckens, fungi<br />
hypogaei terri<strong>to</strong>rii Carpa<strong>to</strong>-Pannonici. Académiai Kiadó,<br />
Budapest.<br />
Taylor FW, Thamage DM, Baker N, Roth-Bejerano N, Kagan-Zur V,<br />
1995. Notes on <strong>the</strong> Kalahari Desert truffle, Terfezia pfeilii.<br />
Mycological Research 99: 874–878.
What <strong>happened</strong> <strong>to</strong> <strong>the</strong> <strong>Tuberales</strong>? 1099<br />
Tedersoo L, Hansen K, Perry BA, Kjøller R, 2006. Molecular and<br />
morphological diversity of pezizalean ec<strong>to</strong>mycorrhiza. New<br />
Phy<strong>to</strong>logist 170: 581–596.<br />
Thiers HD, 1984. The secotioid syndrome. Mycologia 76: 1–8.<br />
Trappe JM, 1971. A synoptis of <strong>the</strong> Carbomycetaceae and Terfeziaceae<br />
(<strong>Tuberales</strong>). Transactions of <strong>the</strong> British Mycological Society 57: 85–92.<br />
Trappe JM, 1975a. The genus Amylascus (<strong>Tuberales</strong>). Transactions of<br />
<strong>the</strong> British Mycological Society 65: 496–499.<br />
Trappe JM, 1975b. The genus Fischerula (<strong>Tuberales</strong>). Mycologia 67:<br />
934–941.<br />
Trappe JM, 1975c. Generic synonyms in <strong>the</strong> <strong>Tuberales</strong>. Mycotaxon 2:<br />
109–122.<br />
Trappe JM, 1977. Biogeography of hypogeous fungi: trees, mammals,<br />
and continental drift. 2nd International Mycological<br />
Congress, Tampa, FL.<br />
Trappe JM, 1979. The orders, families, and genera of hypogeous<br />
Ascomycotina (truffles and <strong>the</strong>ir relatives). Mycotaxon 9: 297–340.<br />
Trappe JM, 1989. Cazia flexiascus gen. et sp. nov., a hypogeous<br />
fungus in <strong>the</strong> Helvellaceae. Memoirs of <strong>the</strong> New York Botanical<br />
Garden 49: 336–338.<br />
Trappe JM, 2001. Taxonomic and nomenclatural problems in <strong>the</strong><br />
genus Tuber. Actes du V e Congrès International Science et Culture<br />
de la Truffe et de autres Champignons Hypoges Comestibles 4–6<br />
Mars 1999, Aix-en-Provence. IPSO, Paris.<br />
Trappe JM, Bea<strong>to</strong>n G, 1984. Mycoclelandia nom. nov. (hypogeous<br />
Ascomycotina), a replacement for <strong>the</strong> pre-empted generic<br />
name Clelandia. Transactions of <strong>the</strong> British Mycological Society<br />
83: 535–536.<br />
Trappe JM, Bushnell W, Castellano MA, 1997. NATS truffle and<br />
truffle-like fungi 6: Stephensia bynumii sp.nov. (Ascomycota),<br />
with a key <strong>to</strong> <strong>the</strong> species of Stephensia. Mycotaxon 64: 431–435.<br />
Trappe JM, Castellano MA, 1992 [1991]. Keys <strong>to</strong> <strong>the</strong> genera of<br />
truffles (Ascomycetes). Mcilvainea 10: 47–65.<br />
Trappe JM, Castellano MA, Claridge A, 2001. Continental drift,<br />
climate, mycophagy and <strong>the</strong> biogeography of <strong>the</strong> hypogeous<br />
fungi. Actes du V e Congrès International Science et Culture de<br />
La Truffe et de autres Champignons Hypoges Comestibles, 4–6<br />
Mars 1999, Aix-en-Provence. IPSO, Paris.<br />
Trappe JM, Castellano MA, Malajczuk N, 1992. Australasian trufflelike<br />
fungi. II. Labyrinthomyces, Dingleya and Reddellomyces gen.<br />
nov. (Ascomycotina). Australian Systematic Botany 5: 597–611.<br />
Trappe JM, Claridge AW, 2006. Australasian sequestrate fungi 17:<br />
<strong>the</strong> genus Hydnoplicata (Ascomycota, Pezizaceae) resurrected.<br />
Australasian Mycologist 25: 33–36.<br />
Trappe JM, Jumpponen AM, Cázares E, 1996. Nats truffle and<br />
truffle-like fungi 5: Tuber lyonii (¼ T. texense), with a key <strong>to</strong><br />
spiny-spored Tuber species group. Mycotaxon 60: 365–372.<br />
Trappe JM, Maser C, 1977. Ec<strong>to</strong>mycorrhizal fungi: interactions of<br />
mushrooms and truffles with beasts and trees. In: Wal<strong>the</strong>rs T<br />
(ed.), Mushrooms and Man. An Interdisciplinary Approach <strong>to</strong><br />
Mycology. Linn-Ben<strong>to</strong>n Community College, Albany, Oregon,<br />
pp. 165–179.<br />
Trappe JM, Sandberg WJ, 1977. Terfezia gigantea (<strong>Tuberales</strong>) in<br />
North America. Mycologia 69: 433–437.<br />
Tulasne L-R, Tulasne C, 1851. Fungi Hypogaei. Paris.<br />
Uecker FA, 1967. Stephensia shanori. I. Cy<strong>to</strong>logy of <strong>the</strong> ascus and<br />
o<strong>the</strong>r observations. Mycologia 59: 819–832.<br />
Urban A, Plattner-Neuner I, Krisai-Greilhuber I, Haselwandtner K,<br />
2002. Detection of an anamorph of Tuber dryophilum: molecular<br />
and immunological evidence. 7th International Mycological<br />
Congress, Oslo.<br />
Verbeken A, Walleyn R, 2003. Una checklist dei funghi ipogei e<br />
secozioidi dell’Africa tropicale. Bolletino del Gruppo Micologico<br />
G. Bresadola 46 (n.s.): 87–96.<br />
Vittadini C, 1831. Monographia Tuberacearum. Milano.<br />
Vizzini A, 2003. Il genere Tuber: la sua posizione nelle Pezizales<br />
(origine dei taxa ipogei nelle Pezizales). Bolletino del Gruppo Micologico<br />
G. Bresadola 46 (n.s.): 97–153.<br />
Vra˚ lstad T, Holst-Jensen A, Schumacher T, 1998. The post-fire<br />
discomycete Geopyxis carbonaria (Ascomycota) is a biotrophic<br />
associate with Norway spruce (Picea abies) in nature. Molecular<br />
Ecology 7: 609–616.<br />
Warcup JH, Talbot PHB, 1989. Muciturbo, a new genus of hypogeous<br />
ec<strong>to</strong>mycorrhizal ascomycetes. Mycological Research 92: 95–100.<br />
Weber NS, Trappe JM, Denison WC, 1997. Studies on western<br />
American Pezizales. Collecting and describing ascomata d<br />
macroscopic features. Mycotaxon 61: 153–176.<br />
Wedén C, Danell E, Tibell L, 2005. Species recognition in <strong>the</strong> truffle<br />
genus Tuber d <strong>the</strong> synonyms Tuber aestivum and Tuber uncinatum.<br />
Environmental Microbiology 7: 1535–1546.<br />
Zak J, Whitford WG, 1986. The occurrence of a hypogeous ascomycete<br />
in <strong>the</strong> nor<strong>the</strong>rn Chihuahuan desert. Mycologia 78:<br />
840–841.<br />
Zambonelli A, Salomoni S, Pisi A, 1993. Caratterizzazione ana<strong>to</strong>momorfologica<br />
delle micorrize di Tuber spp. suQuercus pubescens<br />
Willd. Micologia Italiana 3: 73–90.<br />
Zambonelli A, Iotti M, Amicucci A, Pisi A, 1999. Caratterizzazione<br />
ana<strong>to</strong>mo-morfologica delle micorrize di Tuber maculatum<br />
Vittad. su Ostrya carpinifolia Scop. Micologia Italiana 28:<br />
29–35.<br />
Zhang B-C, 1991a. Taxonomic status of Genabea with two new<br />
species of Genea (Pezizales). Mycological Research 95: 986–994.<br />
Zhang B-C, 1991b. Morphology, cy<strong>to</strong>logy and taxonomy of<br />
Hydnotrya cerebriformis (Pezizales). Mycotaxon 42: 155–162.<br />
Zhang B-C, 1992a. Nuclear numbers in Geneaceae and Terfeziaceae<br />
ascospores and <strong>the</strong>ir taxonomic value. Systema Ascomycetum<br />
11: 31–37.<br />
Zhang B-C, 1992b. Ascospore nuclear number and taxonomy of<br />
truffles. Micologia e Vegetatione Mediterranea 7: 47–53.<br />
Zhang B-C, Minter DW, 1988. Two new species of Labyrinthomyces<br />
from New Zealand, with notes on <strong>the</strong> taxonomy of <strong>the</strong> genus.<br />
Systema Ascomycetum 7: 45–55.<br />
Zhang B-C, Minter DW, 1989a. Morphology, cy<strong>to</strong>logy and<br />
taxonomy of Choiromyces gangliiformis (Ascomycotina, Pezizales).<br />
Mycological Research 92: 91–94.<br />
Zhang B-C, Minter DW, 1989b. Gymnohydnotrya: a new hypogeous<br />
ascomycete genus from Australia. Mycological Research<br />
92: 192–198.