55 (4) • November 2006: 919–930
Smith & al. • Serpocaulon, a new fern genus
Serpocaulon (Polypodiaceae), a new genus segregated from Polypodium
Alan R. Smith1, Hans-Peter Kreier2, Christopher H. Haufler3, Tom A. Ranker4 & Harald
Schneider2
1 University
Herbarium, 1001 Valley Life Sciences Bldg., University of California, Berkeley, California 947202465, U.S.A.; arsmith@berkeley.edu (author for correspondence).
2 Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Abt. Systematische Botanik, Georg-AugustUniversität, Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany.
3 Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045-2106, U.S.A.
4 University Museum and Department of Ecology and Evolutionary Biology, University of Colorado, Boulder,
Colorado 80309, U.S.A.
We describe the neotropical fern genus Serpocaulon (Polypodiaceae), segregated from Polypodium, and make
new combinations for the forty known species. Serpocaulon has been recognized previously as a putatively
natural group by several authors, based on morphological evidence, but never accorded generic rank. The
monophyly of Serpocaulon is strongly supported in chloroplast DNA-based phylogenetic analyses, using the
genes rbcL, rps4, rps4-trnS intergenic spacer, and trnL-F intergenic spacer on 29 samples from 22 species.
Serpocaulon is readily separated from other subclades within Polypodiaceae, and especially from Polypodium,
which is less closely related to Serpocaulon than are several other genera. Serpocaulon differs from other New
World polypods in the combination of usually long-creeping, sparingly branched rhizomes with clathrate
(sometimes strongly so), usually peltately attached scales; regularly anastomosing (goniophlebioid) veins with
individual areoles chevron-shaped and each with a single, free, included excurrent veinlet; and non-paraphysate sori in one to 10 rows between costae and pinna margins. In Polypodium, the rhizome scales are not
clathrate, ± concolorous, and invaginated at the base, with somewhat overlapping basal lobes, and rhizomes
are generally shorter-creeping and more frequently branched, the veins are free or forming a single row of areoles, and the sori uniseriate on each side of the costae. Most species of true Polypodium are north-temperate,
Mexican, or Mesoamerican in distribution, while Serpocaulon is entirely neotropical or subtropical, with the
greatest number of species in South America. There appears to be no convenient infrageneric division of the
species within Serpocaulon, although the most widespread species, S. triseriale, is somewhat isolated at the
base of the clade. Species with the thinnest rhizomes also have the fewest scales, and generally grow at high
elevations. Species having the scaliest rhizomes, with scales spreading and strongly overlapping, form a weakly supported subclade, as do species with multiseriate rows of areoles between costae and pinna margins.
KEYWORDS: ferns, phylogeny, Polypodiaceae, rbcL, rps4, rps4-trnS IGS, Serpocaulon, trnL-F IGS.
INTRODUCTION
The classical Linnaean genus Polypodium, as adopted in most recent floras and taxonomic treatises, comprises about 125–150 species, most of them New World.
Sometimes, additional genera are subsumed within
Polypodium, e.g., Microgramma, Phlebodium, and Pleopeltis in the New World, and Goniophlebium in the Old
World (as by Hennipman & al. in Kubitzki, 1990), in
which case Polypodium exceeds 250 species. Within a
broadly defined, morphologically extremely diverse
Polypodium there are many problematic groups. Recent
molecular evidence suggests that Polypodium s.l. is a
polyphyletic assemblage, even if several segregate genera (e.g., Microgramma, Pecluma, and Campyloneurum)
are excluded (as in most recent tropical floras, e.g., Try-
on & Stolze, 1993; Moran in Davidse & al., 1995; Mickel & Smith, 2004), and that generic boundaries in this
complex of genera (Polypodium s.l.) require substantial
revision (Schneider & al., 2004b).
Within Polypodium s.l. (as applied in floras and taxonomic compendia by most authors today), several
groups have been considered as “natural”, informally
recognized, and taxonomically treated. These include 1)
Polypodium s.s., a group of largely north-temperate species allied to P. vulgare L. (Haufler & al., 1995; Haufler
& Ranker, 1995), with a closely related subgroup, P. plesiosorum and allies (Tejero-Díez & Pacheco, 2004;
Group 1, part, of Tryon & Tryon, 1982), in Mexico and
Central America; 2) P. subpetiolatum and allies (revised
by Maxon, 1903; Group 1, part, of Tryon & Tryon,
1982); 3) the P. furfuraceum and P. plebeium groups
919
Smith & al. • Serpocaulon, a new fern genus
(Maxon, 1916a; 21 spp.; Groups 4 and 6, parts, of Tryon
& Tryon, 1982); 4) P. polypodioides (Maxon, 1916b;
Weatherby, 1939; Group 4, part, of Tryon & Tryon,
1982); 5) P. squamatum and relatives (Maxon, 1916b;
Weatherby, 1947; revised by de la Sota, 1966; 22 spp.;
Group 5, part, of Tryon & Tryon, 1982); 6) the P. thyssanolepis group (Wendt, 1980; Group 4, part, of Tryon &
Tryon, 1982); and 7) P. loriceum, P. fraxinifolium, and
allies, an entirely neotropical group of about 40 species
with regularly anastomosing (goniophlebioid) veins and
often long-creeping, cordlike rhizomes bearing partially
or entirely clathrate scales (most of Group 2 of Tryon &
Tryon, 1982; species taxonomy, 23 spp., revised by
Hensen, 1990). Because nearly all of the major subgroups of Polypodium s.l. occur in Mexico and Central
America, and these areas are a center of diversity for several of the subgroups, many species have been treated in
floristic contexts by Lellinger (1989), Moran (in Davidse
& al., 1995), and by Mickel & Smith (2004). However,
the species allied to P. loriceum and P. fraxinifolium are
predominantly South American and are less well studied,
except for work by Hensen (1990), which was followed
in the main in the floristic account for Peru by Tryon &
Stolze (1993).
Existing evidence (Schneider & al., 2004b) supports
the placement of species in 3) through 6), as delineated
above, in Pleopeltis. All of these groups contain species
that bear scales on the abaxial lamina. A few scaly-bladed species of Polypodium have already been transferred
to Pleopeltis (Windham, 1993), as precursor to their
treatment in the Flora of North America North of Mexico
(Andrews & Windham in FNA Ed. Comm., 1993); however, most scaly species remain in Polypodium, to be
transferred to Pleopeltis elsewhere (Smith & al., in
prep.). Species now placed in the segregate genera
Dicranoglossum, Neurodium, Microphlebodium, and
Pseudocolysis also appear to be closely allied to, and perhaps inseparable from, Pleopeltis s.l. In the present paper
we address the species mentioned under 7) above, and
these lack a name at generic rank. This new genus we
here name Serpocaulon, alluding to the long-creeping,
snakelike rhizomes found in nearly all species.
Many of the species of Serpocaulon were initially
described in Goniophlebium (Blume) C. Presl (see
Appendix 2, electronic supplement), a genus of about 25
species occurring from India, throughout southeast and
eastern Asia, the Himalayan region, and Malesia to
Australasia, Melanesia, Samoa, and Micronesia (RödlLinder, 1990). The name Goniophlebium is derived from
the Greek gonia, meaning angle, and phleps, vein, referring to the characteristic venation pattern formed by regularly anastomosing veins that often form a succession of
chevron-shaped areoles between the pinna midribs and
margins. Although the paleotropical species of Gonio920
55 (4) • November 2006: 919–930
phlebium and the neotropical species of Serpocaulon
have similar venation, and both genera bear clathrate rhizome scales, the similarities are convergent, as indicated
by their positions in phylogenetic trees based on molecular data (see Schneider & al., 2004b). Goniophlebium
s.s. falls within an almost exclusively monophyletic Old
World clade (as far as known, the lone exception is a single disjunct species of Platycerium in the Andes;
Schneider & al., 2004b), whereas Serpocaulon nests in a
predominantly New World clade (with a few African outliers) containing the genera Microgramma, Campyloneurum, Pleopeltis, Pecluma, and Polypodium s.s., as well
as the pantropical grammitid clade. Rödl-Linder (1990)
and Lellinger (1993) also specifically excluded all New
World species of Polypodium from Goniophlebium on
the basis of several morphological characters, e.g., the
absence of black sclerenchyma strands in the rhizomes,
peltate-based rhizome scales, the absence of hairy or
scaly paraphyses in the sori, and the folded perine around
the spores.
In this paper, we restrict the application of
Polypodium L. (Sp. pl. 2: 1082. 1753), with lectotype P.
vulgare L. (chosen by John Smith, Hist. fil. 88. 1875), to
a group of predominantly temperate (mainly north-temperate) species plus a less widespread, tropical and subtropical group of Mexican-Mesoamerican species.
Polypodium, as defined in this narrow sense, then comprises about 15 species in temperate regions of America,
Europe, Asia and Africa (Haufler & al., 1995; Haufler &
Ranker, 1995) and perhaps another 15 species in Mexico
and Mesoamerica. The species have deeply pinnatifid or
weakly 1-pinnate blades, concolorous or sometimes
slightly bicolorous, orange-tan to brown, non-clathrate
rhizome scales, free or weakly anastomosing venation
(each areole with a single, free, included veinlet), sori
terminal on ends of free included veinlets, channeled
stipes, filamentous or branched paraphyses, and more
frequently branched rhizomes.
Within Serpocaulon, eight (of about 40 total) species
have been included previously (as Polypodium) in a phylogenetic study using the chloroplast DNA regions rbcL,
rps4, and rps4-trnS intergenic spacer (Schneider & al.,
2004b): Polypodium adnatum Kunze ex Klotzsch
[voucher re-identified herein as S. richardii (Klotzsch)
Domin], P. fraxinifolium Jacq., P. funckii Mett. (voucher
re-identified as S. ptilorhizon (H. Christ) A. R. Sm.), but
not used in the current study), P. levigatum Cav., P.
patentissimum Mett. ex Kuhn, P. ptilorhizon H. Christ, P.
triseriale Sw., and P. wiesbaueri Sodiro [= P.
eleutherophlebium (Fée) Mett. in this paper]. In a maximum likelihood analysis (Schneider & al., 2004b), this
clade is monophyletic, with clade confidence values of
1.00 (Bayesian posterior probability: PP) and non-parametric bootstrap support of 99%. In the Schneider & al.
55 (4) • November 2006: 919–930
analysis, this clade is weakly supported (Bayesian PP
0.52) as sister to the entire pantropical grammitid clade
(Grammitidaceae, in many classifications), comprising
about 750 species. In molecular analyses, Serpocaulon is
well removed from other species groups currently treated in Polypodium, namely the scaly species (including
Pleopeltis Humb. & Bonpl. ex Willd. s.s., Marginaria
Bory, Polypodium furfuraceum and allies, P. myriolepis
and allies, P. guttatum and allies, Dicranoglossum J. Sm.,
Microphlebodium L. D. Gómez (Gómez, 1985), Pseudocolysis L. D. Gómez (Gómez, 1977), and possibly several other segregate genera) as well as from the
Polypodium vulgare group and from Pecluma M. G.
Price. In the present study, we developed and analyzed
new molecular data from 15 additional species, as well as
incorporating examples from previously sequenced
species, for a total of 22 species now examined—representing slightly more than half of the currently known
species.
It is the objective of this paper to present the molecular and morphological evidence for characterizing
Serpocaulon, formally name the new genus, and effect
transfer of species belonging to it.
MATERIALS AND METHODS
Sequences of four chloroplast DNA regions, rbcL,
rps4, rps4-trnS intergenic spacer, and trnL-F intergenic
spacer, were generated using primers and protocols as
described in previous studies (Haufler & Ranker, 1995;
Schneider & al., 2002, 2004a, b; Haufler & al., 2003;
Janssen & Schneider, 2005). With the exception of newly
generated sequences for samples of Serpocaulon and
trnL-F for Microgramma percussa, all sequences used in
our current study were published in previous papers
(Schneider & al., 2004a, b). The taxon dataset in the current paper is a subset of the one used by Schneider & al.
(2004a), plus additional species of Serpocaulon.
Appendix 1 provides the GenBank accession numbers
for all samples of Serpocaulon, including previously
published sequences. For information concerning
sequences of taxa not belonging to Serpocaulon, except
for Microgramma percussa, see Schneider & al. (2004a).
All sequences were aligned manually using MacClade
4.0 (Maddison & Maddison, 2000). Ambiguously aligning regions were excluded from all analyses.
Phylogenetic analyses were performed using PAUP*
4.0b10 (Swofford, 2000). Dictymia brownii (Wikstr.)
Copel. was chosen as the outgroup representing the loxogrammoid lineage, which has been shown to be the sister lineage of all other polygrammoid ferns (Schneider &
al., 2004b). Maximum parsimony analyses were generated using the heuristic search mode with TBR branch
Smith & al. • Serpocaulon, a new fern genus
swapping, 1000 random addition sequence replicates,
and MULTREES on. Bootstrap values were calculated
with 10,000 bootstrap replicates using the heuristic
search mode with TBR branch swapping and 100 random
addition sequence replicates. The absence of incompatibilities among the four chloroplast DNA regions was
controlled by visual comparison of the results of bootstrap analyses of each of the four cpDNA regions.
Differences were judged to be inconsequential, and the
four regions were combined in all analyses presented.
Maximum likelihood analyses were carried out with
models selected using the hierarchical likelihood test as
implemented in Modeltest (Posada & Crandall, 1998).
The same model, GTR + I + Γ, was selected using the
AIC criterion in Modeltest. It was implemented with the
following parameters: A = 0.2974, C = 0.1980, G =
0.2020, T = 0.2944, A-C = 1.2135, A-G = 3.4737, A-T =
0.4586, C=G = 1.0138, C-T = 4.3370, G-T = 1.000, I =
0.2371, and Γ = 0.999 in the files executed in PAUP*
4.0b10. Tree searches were performed using the heuristic
mode with TBR branch swapping and 100 random addition sequence replications.
Bayesian inference of phylogeny was carried out
with MrBayes 3.0 (Huelsenbeck & Ronquist, 2001) with
the GTR + I + Γ model implemented for 4 chains with
10,000,000 generations, of which each 1000th generation
was sampled. The burn-in phase was identified visually
and excluded before inferring Bayesian posterior probabilities.
RESULTS
Maximum likelihood analysis of the combined
dataset yielded an optimal tree with a -lnL = 0.20233.97
(Fig. 1). Maximum parsimony analysis of the same dataset resulted in 348 most parsimonious trees with a length
of 3023 steps, consistency index of 0.4408, homoplasy
index of 0.5592, retention index of 0.7033, and a
rescaled consistency index of 0.3899 (Fig. 2).
Serpocaulon was monophyletic in maximum likelihood (ML), maximum parsimony (MP), and Bayesian
Inference of phylogeny (BY), with strong support in BY
analysis (Fig. 1, PP = 1.00) and MP analysis (Fig. 2, BS
= 99%). Serpocaulon was not closely related to other
segregates of Polypodium such as Goniophlebium,
Pleopeltis, Pecluma, and Polypodium s.s. Serpocaulon
triseriale was strongly supported as sister to the remaining 21 species of Serpocaulon included in this study
(Figs. 1, 2). In the ML analysis, S. sessilifolium (clade II
in Figs. 1 and 2) was sister to the remaining 20 species.
These 20 species clustered into two clades (clade III + IV
in Fig. 1). One clade included the species S. lasiopus to
S. silvulae (clade III in Fig. 1), whereas the other includ921
Smith & al. • Serpocaulon, a new fern genus
ed S. eleutherophlebium to S. maritimum (clade IV in
Fig. 1). The latter clade had strong support in the BY
analysis (PP = 1.00) and poor bootstrap support in the
MP analysis (BS = 72%). The clade including S. lasiopus
to S. silvulae was not monophyletic in the strict consensus tree of the 348 most parsimonious trees (clade III in
Fig. 2), but it was present in 95% of these trees. In the
S. maritimum Smith s.n.
.
S. appressum Jimenez 862
S. fraxinifolium Jimenez 696
S. giganteum Jimenez 1035
S. richardii Moran 6258
S. richardii Jimenez 1986
S. patentissimum Smith 2829
S. latissimum Jimenez 813
S. intricatum Jimenez 1324
S. latipes Bach 1305
IV
S. intricatum Jimenez 694
S. levigatum Jimenez 756
S. subandinum Hutchinson 5872
S. subandinum Moran 6858
S. ptilorhizon Jimenez 1102
S. eleutherophlebium Smith 2877
S. silvulae Jimenez 1093
S. crystalloneurum Jimenez 1109
S. crystalloneurum Jimenez 1176
S. gilliesii Ehrich 314
III
S. attenuatum Moreno 10406
S. vacillans Mexia 5856a
S. wagneri Smith 1171
S. lasiopus Lewis 35186
S. sessilifolium Jimenez 976
S. sessilifolium Jimenez 755
II
S. sessilifolium Jimenez 806
S. sessilifolium Jimenez 1034
S. triseriale Jimenez 1994
I
Microgramma percussa
Campyloneurum angustifolium
Campyloneurum chlorolepis
Terpsichore *
Adenophorus oahuensis
Pleopeltis angusta
Pleopeltis polypodioides
Polypodium guttatum
Polypodium rosei
Pecluma ptilodon
Polypodium vulgare s.l. *
Polypodium pellucidum
Leptochilus macrophyllus
Microsorum cuspidatum
Microsorum musifolium
Microsorum punctatum
Lemmaphyllum carnosum
Goniophlebium *
Lecanopteris carnosa
Lecanopteris sinuosua
Microsorum linguiforme
Thylacopteris papillosa
Platycerium *
Pyrrosia *
Selliguea feei
Selliguea lanceolata
Selliguea enervis
Selliguea triloba
Selliguea heterocarpa
Arthromeris lehmannii
Aglaomorpha acuminata
Aglaomorpha coronans
Aglaomorpha meyeniana
Drynaria rigidula
Dictymia brownii
55 (4) • November 2006: 919–930
MP analysis, S. sessilifolium (clade II in Fig. 1) was sister to the clade comprising S. eleutherophlebium to S.
maritimum (clade IV in Fig. 1).
All five species represented by more than one specimen formed clades, at least in the ML analysis. The four
specimens of S. sessilifolium formed a strongly supported clade (BS = 100%, Bayesian PP = 1.00). Two specimens of S. subandinum were sister to each other with
bootstrap support of 97% and PP = 1.00. Two specimens
of S. richardii also formed a clade in the ML tree but this
clade was found in only 74% of the MP trees. A Bayesian
PP of 0.98 supported the monophyly of this species. Two
specimens of S. crystalloneuron formed a clade with S.
silvulae in the ML tree, with PP of 1.00, but only 95% of
the most parsimonious trees possessed this clade. The
two specimens of S. intricatum formed a clade with S.
latipes and S. latissimum in both ML and MP trees. This
result was supported by a Bayesian PP of 1.00 and a
bootstrap value of 90%.
72
90
91
93
100
100
99
100
100
100
92
90
100
75
100
97
100
98
100
76
0.01 substitutions/site
Fig. 1. Phylogram with the highest likelihood value found
in the maximum likelihood analysis of the combined
dataset. Thick lines indicate branches with Bayesian posterior probabilities of ≥0.95. The arrow indicates the
Serpocaulon clade. Vertical lines on the right indicate
four clades within Serpocaulon discussed in the results.
Asterisks indicate composite taxa that are based on
sequences generated from two species of an unambiguously monophyletic genus or lineage (see Schneider &
al., 2004a, for further information). All samples of Serpocaulon are given with species name and the corresponding voucher.
922
77
100
98
93
100
100
84
S. maritimum Smith s.n.
S. appressum Jimenez 862
S. fraxinifolium Jimenez 696
S. richardii Moran 6258
S. richardii Jimenez 1986
S. giganteum Jimenez 1035
S. levigatum Jimenez 756
S. patentissimum Smith 2829
S. latissimum Jimenez 813
S. intricatum Jimenez 1324
S. latipes Bach 1305
S. intricatum Jimenez 694
S. subandinum Hutchinson 5872
S. subandinum Moran 6858
S. eleutherophlebium Smith 2877
S. ptilorhizon Jimenez 1102
S. sessilifolium Jimenez 976
S. sessilifolium Jimenez 755
S. sessilifolium Jimenez 806
S. sessilifolium Jimenez 1034
S. silvulae Jimenez 1093
S. crystalloneurum Jimenez 1109
S. crystalloneurum Jimenez 1176
S. gilliesii Ehrich 314
S. attenuatum Moreno 10406
S. lasiopus Lewis 35186
S. wagneri Smith 1171
S. vacillans Mexia 5856a
S. triseriale Jimenez 1994
Microgramma percussa
Campyloneurum angustifolium
Campyloneurum chlorolepis
Pleopeltis angusta
Pleopeltis polypodioides
Polypodium guttatum
Polypodium rosei
Pecluma ptilodon
Polypodium vulgare s.l. *
Polypodium pellucidum
Leptochilus macrophyllus
Microsorum cuspidatum
Microsorum musifolium
Microsorum punctatum
Lemmaphyllum carnosum
Goniophlebium *
Lecanopteris carnosa
Lecanopteris sinuosua
Microsorum linguiforme
Thylacopteris papillosa
Platycerium *
Pyrrosia *
Selliguea feei
Selliguea lanceolata
Selliguea enervis
Selliguea triloba
Selliguea heterocarpa
Arthromeris lehmannii
Aglaomorpha acuminata
Aglaomorpha coronans
Aglaomorpha meyeniana
Drynaria rigidula
Terpsichore *
Adenophorus oahuensis
Dictymia brownii
IV
II
III
I
Fig. 2. Strict consensus tree of 348 most parsimonious
trees obtained in a maximum parsimony analysis of the
combined dataset. Bootstrap values >70% are given
above branches. For further information see Fig. 1.
55 (4) • November 2006: 919–930
DISCUSSION
The monophyly of Serpocaulon is strongly supported in all analyses of the cpDNA sequence data, data that
include slightly more than half of the currently accepted
species. In all phylogenetic analyses, the lineage is
clearly separated from other lineages traditionally
assigned to Polypodium s.l. (Schneider & al., 2004a, b),
and it is unambiguous whether a given species of
Polypodium s.l. is included or not. Serpocaulon appears
morphologically well-defined and has been recognized
previously as a putative natural group by various authors
(Tryon & Tryon, 1982, Group 2; Hensen, 1990),
although Tryon and Tryon included three species that
both we and Hensen exclude: Polypodium decumanum
Willd. [= Phlebodium decumanum (Willd.) J. Sm.], P.
decurrens Raddi [= Campyloneurum decurrens (Raddi)
C. Presl], and Polypodium kunzeanum C. Chr.].
Lellinger’s (1993) definition of Polypodium subg. Polygoniophlebium roughly coincides with our circumscription of Serpocaulon, except that we exclude Polypodium
plectolepidioides Rosenst. and P. rhachypterygium
Liebm. (which may be more closely related to
Pecluma), as well as P. plesiosorum Kunze (which we
retain in a redefined and smaller Polypodium; see
Tejero-Díez & Pacheco, 2004); all three of these species
were mentioned by Lellinger as belonging to subg.
Polygoniophlebium.
Hensen (1990) attempted a revision of the Polypodium loriceum group (our genus Serpocaulon) based
on morphological characters, and several new species
have been described since (Kessler & Smith, 2005).
Because Hensen’s (1990) circumscription of the “loriceum” group is basically the same as ours, it is of interest
to compare the results of his morphology-based cladistic
analysis with our molecular results. With Hensen’s
dataset, homoplasy was acknowledged to be a major
problem. A further problem was his selection of
Campyloneurum as outgroup, because this genus may
not be the closest relative of Serpocaulon (Schneider &
al., 2004b). Hensen assessed 18 characters of the rhizomes, rhizome scales, fronds, indument, and spores, and
his consensus cladogram shows two major lineages, one
of which corresponds in part with a clade found in all
analyses of our cpDNA dataset that was strongly supported in BY (PP =1.00) but poorly supported in MP (BS
= 72%) (Fig. 2, clade IV). This clade includes taxa with
less scaly rhizomes, with many of the species having
wholly or partly appressed scales. Hensen’s “scaly” clade
also included S. sessilifolium, which is either sister to the
other major clade (Clade IV) of Serpocaulon (MP) or sister to clades III + IV (ML) based on our cpDNA evidence. Taking into account the basal position of S. triseriale, the cpDNA data suggest a trend from densely scaly
Smith & al. • Serpocaulon, a new fern genus
rhizomes towards less dense indument and decreasing
size of the scales in this genus. In Hensen’s analysis, S.
triseriale was sister to a clade that included taxa with
reduced indument density. This result may reflect the
presence of many plesiomorphic features in this putatively earliest diverging species of Serpocaulon.
We see other resemblances of putatively related
species in the Hensen cladogram and our molecular tree.
These include 1) a Hensen-clade containing species with
1-pinnate blades and 3+ rows of areoles and sori between
costae and pinna margins (containing S. appressum, S.
fraxinifolium, S. richardii, and two other species not
sampled by us, S. adnatum and S. caceresii—a subset of
our clade IV in the ML analysis (Fig. 1); and 2) a clade
containing most of the species with densely scaly rhizomes (comprising S. crystalloneuron, S. gilliesii, S.
lasiopus, S. vacillans, and S. wagneri)—basically, our
clade III in the ML analysis (Fig. 1). Thus, the genealogical composition of both Hensen’s morphology-based
tree and our molecular tree show similarities, although
some of the results are difficult to compare because sampling in the two studies differed, and we have also adopted different circumscription of certain species.
Currently, evidence suggests some trends in the morphological evolution of Serpocaulon. Densely scaly rhizomes appear to be plesiomorphic, with a trend toward
reduction in the number and size of scales on the rhizomes. Narrowing of the rhizome diameter also seems to
be correlated with scale reduction. Species with the thinnest rhizomes (smallest diameter) and fewest scales form
a grade at the base of our clade IV in the ML analysis
(Fig. 1): S. eleutherophlebium, S. ptilorhizon, S. subandinum, and S. levigatum; however, S. patentissimum,
with the fewest rhizome scales and thinnest rhizomes, is
not clearly part of this clade. Not only is scale number
reduced in these species, but the rhizome scales are often
tightly appressed, or spreading only at the scale tips; the
ultimate reduction is seen in S. patentissimum, S. levigatum, and S. ptilorhizon, where the rhizomes are subglabrous; these species tend to grow at high elevations.
Species having dense, persistent, spreading, and strongly
overlapping scales fall toward the base of the tree in both
ML and MP analyses (Figs. 1–2): S. attenuatum, S. crystalloneuron, S. gilliesii, S. lasiopus, S. sessilifolium, S.
triseriale, and S. wagneri. Several of these grow at low
elevations, and all except S. triseriale have a single row
of sori on each side of the costa.
Another trend within Serpocaulon appears to be
increasing pinnation (ultimately to completely free, nonadnate pinnae) in the clade comprising S. maritimum, S.
fraxinifolium, S. appressum, S. giganteum, and S. richardii. Several other unsampled species are expected to fall
within this clade, e.g., S. caceresii and S. adnatum. Those
species showing increased pinnation (free non-adnate
923
Smith & al. • Serpocaulon, a new fern genus
pinnae) also show a greater number of rows of areoles
(and sori) between the costae and pinna margins.
Serpocaulon is related to several genera with an exclusively or nearly exclusively neotropical distribution.
We refrain from drawing conclusions about the closest
relative until denser sampling of the putative closest lineages, such as Microgramma and the grammitids, can be
performed. In Schneider & al. (2004b), Serpocaulon was
found to be sister to grammitids, but these relationships
were poorly supported. Further evidence is needed to
confirm this hypothesis or to confirm alternative hypotheses such as close relationships between Microgramma
and Serpocaulon or between Campyloneurum and Serpocaulon. Further sampling must also precede exploration
of the radiation of Serpocaulon in the Neotropics and
possible correlations between the origin of Andean habitats and the diversification of the genus in that area,
home of nearly three-fourths of the species in the genus.
We note that the basalmost species in the genus, S. triseriale, has the largest distribution of any species in Serpocaulon, covering nearly the entire distribution of the genus latitudinally (but not elevationally). Biogeographical
and ecological trends can be only generally stated using
existing data: (1) Serpocaulon shows the greatest diversity in South America; (2) species occurring at lowest
elevations in the genus, usually below 500 m, appear to
be members of the basalmost branches of the tree (S.
attenuatum, primarily Amazonian; S. triseriale, mostly
100–1500 m; and S. wagneri, mostly 0–1000 m); and (3)
those species having thinnest rhizomes and fewest scales
are entirely or predominantly middle- to high-Andean, in
comparison to many of the other species of Serpocaulon,
which are more widespread, in montane forests, or mainly at low to middle elevations.
Although the current sampling is insufficient to draw
conclusions about the relationships among the species of
Serpocaulon as well as the monophyly of some species,
this summary illustrates that the sampling is adequate to
outline some issues that need to be considered in future
studies and in any exhaustive revision of the genus. A
denser taxon sampling with additional molecular markers must be obtained before these issues are explored in
detail.
TAXONOMIC TREATMENT
Serpocaulon A. R. Sm., gen. nov. – Type: Serpocaulon loriceum (L.) A. R. Sm. [≡ Polypodium loriceum
L.]. Figs. 3, 4.
Polypodium L. subg. Polygoniophlebium Lellinger,
Amer. Fern J. 83: 37. 1993. – Type: Polypodium fraxinifolium Jacq. [≡ Serpocaulon fraxinifolium (Jacq.) A.R.
Sm.]
924
55 (4) • November 2006: 919–930
A Polypodio sensu stricto venis ordinate anastomosantibus, areolis cheveroniformibus (similaribus
Goniophlebio et Thelypteridi subg. Meniscio), 1–10jugatis inter costas et margines pinnarum, omnis areolis
venula singulari inclusa excurrenti libero, paleis rhizomatum clathratis, minimum centraliter vel basaliter, generaliter peltatis, rhizomatibus plerumque longirepentibus,
parce ramosis, distributione neotropico differt; a Pleopelti
sensu lato laminis pinnatisectis vel 1-pinnatis, paleis carentibus abaxialiter et adaxialiter in venis et interveniis differt; a Pecluma venis ordinate anastomosantibus differt.
Epiphytic or epipetric, infrequently terrestrial.
Rhizomes usually very long-creeping, short-creeping in a
few species, sparingly branched, the phyllopodia
(0.5)5–20 times the rhizome width apart, sometimes glaucous, root proliferations absent; black sclerenchyma
strands absent; vascular bundles sometimes with sclerenchyma sheaths; scales round, oblong, lanceolate, or
lanceolate-attenuate and with a filiform tip, bicolorous,
part of each scale clathrate with the side walls dark brown
or black, sometimes the lumina also blackish so that the
scales appear completely black, generally peltately
attached (or with strongly overlapping lobes at a deeply
cordate base), surfaces glabrous (lacking rhizoidal surface
indument), margins entire or toothed. Stipes stramineous
to light brownish, nearly terete proximally, flattened to
channeled distally. Blades pinnatifid to pinnate, rarely
simple (S. levigatum) or shallowly pinnatifid, monomorphic, stipitate, articulate on short phyllopodia; laminae
glabrous, hairy, with scales absent, or scattered clathrate
scales present along the costae and a few on the rachises;
veins regularly anastomosing (goniophlebioid), areoles
chevron-shaped and each with a single, free, included
vein. Sori round or nearly so, in one to 10 rows between
costae and margins, exindusiate, each sorus terminal on a
free included vein; paraphyses absent or present and
short, 2–3-celled, glandular, not easily seen; sporangia
glabrous. Spores light yellowish to whitish, bilateral, exine
verrucate, perispore relatively thin or occasionally thickened, generally tuberculate, occasionally winged; x = 37.
Distribution: ca. 40 species, several recently
described (Kessler & Smith, 2005), and several more
needing description. Preponderantly S. American, but
with 14 species extending or restricted to the Antilles,
Central America, and southern Mexico (S. antillense, S.
attenuatum, S. dissimile, S. eleutherophlebium, S. falcaria, S. fraxinifolium, S. giganteum, S. levigatum, S.
loriceum, S. loriciforme, S. maritimum, S. ptilorhizon, S.
triseriale, S. wagneri). The only species restricted to the
Antilles or to North America north of Colombia are S.
antillense and S. falcaria, while 26 species are confined
to South America.
Serpocaulon differs from Polypodium in having regularly anastomosing (goniophlebioid) veins with individ-
55 (4) • November 2006: 919–930
Smith & al. • Serpocaulon, a new fern genus
Fig. 3. Serpocaulon species. A, S. caceresii, portion of pinna, with multiseriate sori; B, S. dissimile, portion of clathrate
scale; C, S. fraxinifolium, glaucous rhizomes, with sparse round scales; D, S. dasypleuron, portion of pinnatisect blade,
with uniseriate sori; E, S. levigatum, portions of simple blades; F, S. triseriale, fronds, with 1-pinnate blades; G, S. fraxinifolium, portion of pinna; H, S. dissimile, portion of pinnae. Photo credits: R. C. Moran, http://www.plantsystematics.org/
925
Smith & al. • Serpocaulon, a new fern genus
55 (4) • November 2006: 919–930
Fig. 4. Serpocaulon species. A–C, S. dissimile (Hallberg 1281, NY). A, pinnae and rhizome; B, pinna detail; C, rhizome
scale. D–F, S. falcaria (Mickel 1527, NY). D, pinnae; E, pinna detail; F, rhizome scale. G–K, S. fraxinifolium (Türckheim
642, NY). G, pinnae; H, rhizome; J, rhizome scale; K, pinna detail. L–O, S. triseriale (Hallberg 1284, NY). L, pinnae; M,
pinna detail; N, rhizome; O, rhizome scale. 3 cm bar scale applies to A, D, G, and L; smaller, unlabeled bar scales are
1 mm and apply to rhizome scales. Reproduced with permission from Mickel & Smith (2004).
926
55 (4) • November 2006: 919–930
ual areoles chevron-shaped and each with a single, free,
included veinlet; sori are in one to 10 rows between
costae and margins (Figs. 3–4). Polypodium has veins
free, casually anastomosing, or (especially in Mexican
and Mesoamerican species) with areoles forming a single
row between costae and pinna margins, and species have
only a single row of sori on each side of the costae.
Additionally, the rhizome (and costal scales, if present)
in Serpocaulon are clathrate (Fig. 3B), sometimes
strongly so, at least in the central or basal part of the
scales, although in some species, the lumina are also
rather blackish or obscure; rhizome scales are also usually peltately attached at their base, or with a deeply cordiform base with strongly overlapping lobes (e.g., in S. sessilifolium). In Polypodium, the rhizome scales are ± concolorous and invaginated at the base, with somewhat
overlapping basal lobes. Rhizomes of Serpocaulon are
generally much longer-creeping and less frequently
branched than in Polypodium (Figs. 3C, 4A, H, N).
Polypodium s.s. is largely north-temperate, Mexican, and
Mesoamerican, while Serpocaulon is tropical or subtropical in distribution, with most species in South America.
From Pleopeltis, Serpocaulon differs in the absence
of scales on veins and tissue between veins and generally
easily visible venation. Many species of Serpocaulon
have glandular or acicular hairs (Figs. 3D, 4B), which are
lacking in most species of Pleopeltis. Pecluma differs
from Serpocaulon in having free or sporadically anastomosing veins, a single row of sori on each side of the
costae, often reduced proximal pinnae, non-clathrate,
often comose rhizome scales, generally short-creeping
rhizomes, and pinnatisect blades with usually more than
30 pairs of pinnae per blade and pinnae usually dilated at
the base. Phlebodium differs from Serpocaulon in the
shorter-creeping, generally much scalier rhizomes, nonclathrate, reddish to orangish, concolorous, spreading
scales, the vein areoles more irregularly arranged, and by
the sori served by two excurrent veinlets that are joined at
their tips; Phlebodium is only remotely related to Serpocaulon in phylogenetic analyses (Schneider & al., 2004b).
Serpocaulon comprises several somewhat ill-defined
and informal morphological groups: (1) the S. loriceum
group (S. dasypleuron, S. falcaria, S. intricatum, S. latipes, S. latissimum, S. loriceum; Figs. 3D, 4D–F), with
rhizomes glaucous or not, rhizome scales scattered (or
rhizome nearly naked) to dense, clathrate, at least centrally, round to ovate to ovate-lanceolate, blades pinnatisect, or with strongly adnate and often surcurrent pinna;
veins anastomosing in 1 (occasionally 2 or 3) row(s),
scattered scales present on midribs abaxially, these dark
and clathrate; (2) the S. fraxinifolium group (S. adnatum,
S. appressum, S. caceresii, S. fraxinifolium, S. giganteum, S. richardii; Figs. 3A, C, G, 4G–K), with rhizomes
not glaucous, scales scattered (or rhizomes nearly naked)
Smith & al. • Serpocaulon, a new fern genus
to dense, decidedly clathrate (at least centrally) and
round to ovate to ovate-attenuate, blades 1-pinnate with
pinnae sessile or adnate, not surcurrent, veins regularly
anastomosing in (1–)2–10 series between midribs
(costae) and pinna margins; (3) the S. subandinum group
(S. eleutherophlebium, S. funckii, S. levigatum, S. ptilorhizon; Fig. 3E), with narrow, sparsely scaly, sometimes
glaucous rhizomes, pinnatisect blades (simple in S. levigatum); and (4) the S. lasiopus group (S. catharinae, S.
crystalloneuron, S. dissimile, S. lasiopus, S. panorense,
and S. wagneri; Figs. 3B, 4A–C), with rhizomes densely
scaly, scales usually spreading, blades pinnatisect or 1pinnate with adnate pinnae.
Chromosome numbers reported for species of Serpocaulon are diploid, 2n = 37 II (or 2n = 74) for most species, a common number in Polypodiaceae: Polypodium
ptilorhizon and P. fraxinifolium (Sorsa, 1966);
Polypodium chnoodes (Walker, 1966); and Polypodium
loriceum and P. triseriale (Smith & Mickel, 1977;
Walker, 1985). The tetraploid condition, 2n = 74 II, has
also been reported for P. triseriale (Walker, 1966). x = 37
is by far the commonest base number in neotropical
polypodioid ferns, and also occurs in Polypodium s.s.
The spores of Serpocaulon are typical of other polypods, light yellowish to whitish, ellipsoid or reniform
and monolete, and with a generally tuberculate perispore
(e.g., Serpocaulon levigatum, S. latipes, S. maritimum, S.
meniscifolium, S. subandinum, and S. triseriale; Hensen,
1990) surrounding a low-verrucate exospore (e.g.,
Serpocaulon latipes, Tryon & Lugardon, 1991: 344; S.
wagneri, Hensen 1990: fig. 62). The illustration of the
spores of S. sessilifolium by both Hensen (1990) and by
Tryon and Lugardon (1991: fig. 131.6) shows a perispore
with loose folds (wings) that appears unlike most other
members of the genus. Serpocaulon wagneri also has
low perispore folds overlying a low-tuberculate pattern.
New combinations:
Serpocaulon adnatum (Kunze ex Klotzsch) A.R. Sm.,
comb. nov. ≡ Polypodium adnatum Kunze ex
Klotzsch, Linnaea 20: 395. 1847. – Distribution:
Colombia, Venezuela, and Guianas to Bolivia, Brazil.
Serpocaulon antillense (Maxon) A.R. Sm., comb. nov.
≡ Polypodium antillense Maxon, Proc. Biol. Soc.
Wash. 43: 83. 1930. – Distribution: Cuba, Jamaica,
Hispaniola, Guadeloupe, Martinique. Guayanan
Venezuela?
Serpocaulon appressum (Copel.) A.R. Sm., comb. nov.
≡ Polypodium appressum Copel., Univ. Calif. Publ.
Bot. 10: 305, pl. 66. 1941. – Distribution: Peru,
Bolivia.
Serpocaulon attenuatum (Humb. & Bonpl. ex Willd.)
A.R. Sm., comb. nov. ≡ Polypodium attenuatum
Humb. & Bonpl. ex Willd., Sp. pl., ed. 4, 5: 191.
927
Smith & al. • Serpocaulon, a new fern genus
1810. – Distribution: Nicaragua to Panama, Venezuela, Guianas, Colombia to Bolivia, Brazil.
Serpocaulon caceresii (Sodiro) A.R. Sm., comb. nov.
(Fig. 3A) ≡ Polypodium caceresii Sodiro, Crypt.
vasc. quit. 360. 1893. – Distribution: Colombia to
Bolivia and French Guiana, Brazil.
Serpocaulon catharinae (Langsd. & Fisch.) A.R. Sm.,
comb. nov. ≡ Polypodium catharinae Langsd. &
Fisch., Pl. voy. Russes monde 1, t. 9. 1810. –
Distribution: Brazil.
Serpocaulon chacapoyense (Hook.) A.R. Sm., comb.
nov. ≡ Polypodium chacapoyense Hook., Hooker’s
Icon. 1: t. 69. 1937. – Distribution: Peru.
Serpocaulon concolorum (M. Kessler & A.R. Sm.) A.R.
Sm., comb. nov. ≡ Polypodium concolorum M.
Kessler & A.R. Sm., Candollea 60: 277. 2005. –
Distribution: Bolivia.
Serpocaulon crystalloneuron (Rosenst.) A.R. Sm.,
comb. nov. ≡ Polypodium crystalloneuron Rosenst.,
Repert. Spec. Nov. Regni Veg. 11: 57. 1912. –
Distribution: Peru, Bolivia.
Serpocaulon dasypleuron (Kunze) A.R. Sm., comb. nov.
(Fig. 3D) ≡ Polypodium dasypleuron Kunze, Linnaea 9: 43. 1834. – Distribution: Colombia to
Bolivia.
Serpocaulon dissimile (L.) A.R. Sm., comb. nov. (Figs.
3B, 3H, 4A–C) ≡ Polypodium dissimile L., Syst.
Nat., ed. 10. 2: 1325. 1759. – Distribution: S.
Mexico to Ecuador, Antilles, Trinidad.
Serpocaulon eleutherophlebium (Fée) A.R. Sm., comb.
nov. ≡ Goniophlebium eleutherophlebium Fée,
Mém. foug. 5: 255. 1852. – Distribution: Costa Rica,
Panama, Colombia, Venezuela, Ecuador.
Serpocaulon falcaria (Kunze) A.R. Sm., comb. nov.
(Fig. 4D–F) ≡ Polypodium falcaria Kunze, Linnaea
18: 316. 1844 [1845]. – Distribution: S. Mexico to
Honduras.
Serpocaulon fraxinifolium (Jacq.) A.R. Sm., comb.
nov. (Figs. 3C, 3G, 4G–K) ≡ Polypodium fraxinifolium Jacq., Collectanea 3: 187. 1789. – Distribution:
Mexico to Bolivia, Guianas, S. Brazil.
Serpocaulon funckii (Mett.) A.R. Sm., comb. nov. ≡
Polypodium funckii Mett., Abh. Senckenberg.
Naturf. Ges. 2: 57. 1857. – Distribution: Venezuela
and Colombia to Bolivia.
Serpocaulon giganteum (Desv.) A.R. Sm., comb. nov. ≡
Polypodium giganteum Desv., Mém. Soc. Linn.
Paris 6: 236. 1827. – Distribution: Costa Rica to
Bolivia, S. Brazil.
Serpocaulon gilliesii (C. Chr.) A.R. Sm., comb. nov. ≡
Polypodium gilliesii C. Chr., Index fil. 529. 1906. (a
nom. nov. for Polypodium pubescens Hook. & Grev.
(non L., 1759). – Distribution: Peru, Bolivia, NW.
Argentina.
928
55 (4) • November 2006: 919–930
Serpocaulon intricatum (M. Kessler & A.R. Sm.) A.R.
Sm., comb. nov. ≡ Polypodium intricatum M.
Kessler & A.R. Sm., Candollea 60: 278. 2005. –
Distribution: Ecuador, Peru, Bolivia.
Serpocaulon lasiopus (Klotzsch) A.R. Sm., comb. nov.
≡ Polypodium lasiopus Klotzsch, Linnaea 20: 393.
1847. – Distribution: Venezuela, Ecuador, Peru,
Bolivia.
Serpocaulon latipes (Langsd. & Fisch.) A.R. Sm., comb.
nov. ≡ Polypodium latipes Langsd. & Fisch., Pl. voy.
Russes monde (Icon. Fil.) 1: 10, t. 10. 1810. –
Distribution: Bolivia, S. Brazil.
Serpocaulon latissimum (R.C. Moran & B. Øllg.) A.R.
Sm., comb. nov. ≡ Polypodium latissimum R.C.
Moran & B. Øllg., Nordic J. Bot. 15: 184. 1995. –
Distribution: Ecuador, Bolivia.
Serpocaulon levigatum (Cav.) A.R. Sm., comb. nov.
(Fig. 3E) ≡ Polypodium levigatum Cav., Descr. Pl.
244. 1801. – Distribution: Costa Rica, Guadeloupe,
Colombia to Guianas and Bolivia.
Serpocaulon loriceum (L.) A.R. Sm., comb. nov. ≡
Polypodium loriceum L., Sp. Pl. 2: 1086. 1753. –
Distribution: Nicaragua to Panama, Antilles,
Trinidad, Colombia, Venezuela, Guianas.
Serpocaulon loriciforme (Rosenst.) A.R. Sm., comb.
nov. ≡ Polypodium loriciforme Rosenst., Repert.
Spec. Nov. Regni Veg. 22: 17. 1925. – Distribution:
Costa Rica to Peru.
Serpocaulon maritimum (Hieron.) A.R. Sm., comb. nov.
≡ Polypodium maritimum Hieron., Bot. Jahrb. Syst.
34: 527. 1904. – Distribution: Nicaragua to Peru.
Serpocaulon meniscifolium (Langsd. & Fisch.) A.R.
Sm., comb. nov. ≡ Polypodium meniscifolium
Langsd. & Fisch., Pl. Voy. Russes Monde 11, pl. 11.
1810. – Distribution: S. Brazil.
Serpocaulon mexiae (Copel.) A.R. Sm., comb. nov. ≡
Polypodium mexiae Copel., Univ. Calif. Publ. Bot.
17: 233. 1941. – Distribution: Minas Gerais, Brazil.
Serpocaulon nanegalense (Sodiro) A.R. Sm., comb.
nov. ≡ Polypodium nanegalense Sodiro, Recens.
Crypt. vasc. quit. 65. 1883. – Distribution:
Colombia, Ecuador.
Serpocaulon panorense (C. Chr.) A.R. Sm., comb. nov.
≡ Polypodium panorense C. Chr., Dansk Bot. Ark.
6(3): 97. 1929. – Distribution: Guyana (vide Hensen,
1990), Brazil.
Serpocaulon patentissimum (Mett. ex Kuhn) A.R. Sm.,
comb. nov. ≡ Polypodium patentissimum Mett. ex
Kuhn, Linnaea 36: 134. 1869. – Distribution:
Colombia, Ecuador.
Serpocaulon polystichum (Link) A.R. Sm., comb. nov.
≡ Polypodium polystichum Link, Hort. Reg. Bot.
Berol. 2: 101. 1833. – Distribution: Ecuador to
Bolivia.
55 (4) • November 2006: 919–930
Serpocaulon ptilorhizon (H. Christ) A.R. Sm., comb.
nov. ≡ Polypodium ptilorhizon H. Christ, Bull. Herb.
Boissier, sér. 2, 5: 6. 1905. – Distribution: Nicaragua
to Bolivia.
Serpocaulon richardii (Klotzsch) A.R. Sm., comb. nov.
≡ Polypodium richardii Klotzsch, Linnaea 20: 394.
1847. – Distribution: Guianas, Venezuela, Colombia
to Bolivia, Brazil.
Serpocaulon semipinnatifidum (Fée) A.R. Sm., comb.
nov. ≡ Goniophlebium semipinnatifidum Fée, Mém.
Foug. 5: 256. 1852. – Distribution: Colombia,
Venezuela, Peru.
Serpocaulon sessilifolium (Desv.) A.R. Sm., comb. nov.
≡ Polypodium sessilifolium Desv., Mém. Soc. Linn.
Paris 6: 238. 1827. – Distribution: Venezuela and
Colombia to Bolivia.
Serpocaulon silvulae (M. Kessler & A.R. Sm.) A.R.
Sm., comb. nov. ≡ Polypodium silvulae M. Kessler
& A.R. Sm., Candollea 60: 280. 2005. –
Distribution: Bolivia.
Serpocaulon subandinum (Sodiro) A.R. Sm., comb.
nov. ≡ Polypodium subandinum Sodiro, Crypt. vasc.
quit. 348. 1893. – Distribution: Ecuador and Peru.
Serpocaulon triseriale (Sw.) A.R. Sm., comb. nov. (Fig.
3F, 4L–O) ≡ Polypodium triseriale Sw., J. Bot.
(Schrader) 1800(2): 126. 1801. – Distribution: S.
Mexico to Bolivia, Guianas, Brazil, Paraguay;
Antilles, Trinidad.
Serpocaulon vacillans (Link) A.R. Sm., comb. nov. ≡
Polypodium vacillans Link, Hort. berol. 2: 97. 1833.
– Distribution: Bolivia, S. Brazil, Paraguay.
Serpocaulon wagneri (Mett.) A.R. Sm., comb. nov. ≡
Polypodium wagneri Mett., Ann. Sci. Nat. Bot., sér.
5, 2: 255. 1864. – Distribution: Costa Rica to
Venezuela and Ecuador.
Excluded species:
Polypodium kunzeanum C. Chr. – Cited by Tryon and
Stolze (1993) as a synonym of P. sessilifolium Desv.,
which we believe is not closely related. Polypodium kunzeanum (Costa Rica to Peru and Brazil) has much less
regular venation, sometimes with two included and themselves anastomosing veins within an areole, cordatebased, non-adnate pinnae (the basalmost with lobes overlapping the rachis), and non-clathrate rhizome scales.
ACKNOWLEDGEMENTS
We thank Charles Alford, Ivan Jimenez, Robbin Moran,
Michael Kessler, and staff of The University of California
Botanical Garden for providing samples of Serpocaulon. Thanks
also to Daniel Tejero-Díez and to an anonymous reviewer, for
reading and commenting on the manuscript. This research was
Smith & al. • Serpocaulon, a new fern genus
supported by a collaborative grant from the National Science
Foundation to ARS (DEB-9807053), CHH (DEB-9807054), and
TAR (DEB-9726607), as well as support to HS from the German
Science Foundation (DFG; SCHN 758/2-1) (under the
Schwerpunkt Programm SPP 1127, “Radiations—Origin of
Biological Diversity”.
LITERATURE CITED
Davidse, G., Sousa, M. & Knapp, S. (gen. eds.). 1995. Flora
Mesoamericana. Vol. 1. Psilotaceae a Salviniaceae. R. C.
Moran and R. Riba (Pteridophyte eds.). Univ. Nacional
Autónoma de México, Ciudad Universitaria.
de la Sota, E. R. 1966. Revisión de las especies americanas del
grupo Polypodium squamatum L. Revista Mus. La Plata,
Secc. Bot. 10: 69–186.
Flora of North America Editorial Committee [FNA Ed.
Comm.]. 1993. Flora of North America North of Mexico,
Vol. 2, Pteridophytes and Gymnosperms. Oxford Univ.
Press, Oxford.
Gómez, L. D. 1977. Contribuciones a la pteridologia centroamericana: 2. Novitates. Brenesia 10/11: 115–119.
Gómez, L. D. 1985. Microphlebodium, un nuevo nombre
generico (Polypodiaceae). Phytologia 59: 58.
Haufler, C. H., Grammer, W. A., Hennipman, E., Ranker, T.
A., Smith, A. R. & Schneider, H. 2003. Systematics of
the ant-fern genus Lecanopteris (Polypodiaceae): testing
phylogenetic hypothesis with DNA sequences. Syst. Bot.
28: 217–227.
Haufler, C. H. & Ranker, T. A. 1995 [1996]. RbcL sequences
provide phylogenetic insights among sister species of the
fern genus Polypodium. Amer. Fern J. 85: 361–374.
Haufler, C. H., Soltis, D. E. & Soltis, P. S. 1995. Phylogeny
of the Polypodium vulgare complex: insights from chloroplast DNA restriction site data. Syst. Bot. 20: 110–119.
Hensen, R. V. 1990. Revision of the Polypodium loriceum
complex (Filicales, Polypodiaceae). Nova Hedwigia 50:
279–336.
Huelsenbeck, J. P. & Ronquist, F. 2001. MrBayes: Bayesian
inference of phylogenetic trees. Bioinformatics 17:
754–755.
Janssen, T. & Schneider, H. 2005. Exploring the evolution of
humus collecting leaves in drynarioid ferns
(Polypodiaceae, Polypodiidae). Pl. Syst. Evol. 252:
175–197.
Kessler, M. & Smith, A. R. 2005. Seven new species, 13 new
combinations, and one new name of Polypodiaceae from
Bolivia. Candollea 60: 271–288.
Kubitzki, K. (ed.) 1990. The Families and Genera of Vascular
Plants. Vol. 1. Pteridophytes and Gymnosperms. Springer,
Berlin.
Lellinger, D. B. 1989. The ferns and fern-allies of Costa Rica,
Panama, and the Chocó (Part 1: Psilotaceae through
Dicksoniaceae). Pteridologia 2A: 1–364.
Lellinger, D. B. 1993. Application of the name Goniophlebium
and a new subgeneric name in Polypodium. Amer. Fern J.
83: 37–38.
Maddison, D. R. & Maddison, E. P. 2000. MacClade 4.0.
Sinauer Associates, Sunderland.
929
Smith & al. • Serpocaulon, a new fern genus
Maxon, W. R. 1903. A study of certain Mexican and
Guatemalan species of Polypodium. Contr. U.S. Natl.
Herb. 8: 271–280.
Maxon, W. R. 1916a. Studies of tropical American ferns. No.
6. Polypodium furfuraceum and related species. Contr.
U.S. Natl. Herb. 17: 557–579.
Maxon, W. R. 1916b. Studies of tropical American ferns. No.
6. Polypodium squamatum and its allies. Contr. U.S. Natl.
Herb. 17: 579–596.
Mickel, J. T. & Smith, A. R. 2004. The pteridophytes of
Mexico. Mem. New York Bot. Gard. 88: i–xxiv, 1–1055.
Posada, D. & Crandall, K. A. 1998. Modeltest: testing the
model of DNA substitution. Bioinformatics 14: 817–818.
Rödl-Linder, G. 1990. A monograph of the fern genus
Goniophlebium (Polypodiaceae). Blumea 34: 277–423.
Schneider, H., Smith, A. R., Cranfill, R., Haufler, C. H.,
Ranker, T. A. & Hildebrand, T. 2002. Gymnogrammitis
dareiformis is a polygrammoid fern (Polypodiaceae)—
resolving an apparent conflict between morphological and
molecular data. Pl. Syst. Evol. 234: 121–136.
Schneider, H., Janssen, T., Hovenkamp, P., Smith, A. R.,
Cranfill, R., Haufler, C. H. & Ranker, T. A. 2004a.
Phylogenetic relationships of the enigmatic Malesian fern
Thylacopteris (Polypodiaceae, Polypodiidae). Int. J. Pl.
Sci. 165: 1077–1087.
Schneider, H., Smith, A. R., Cranfill, R., Hildebrand, T. E.,
Haufler, C. H. & Ranker, T. A. 2004b. Unraveling the
phylogeny of polygrammoid ferns (Polypodiaceae &
Grammitidaceae): exploring aspects of the diversification
of epiphytic plants. Molec. Phylog. Evol. 31: 1041–1063.
Smith, A. R. & Mickel, J. T. 1977. Chromosome counts for
Mexican ferns. Brittonia 29: 391–398.
55 (4) • November 2006: 919–930
Sorsa, V. 1966. Chromosome studies in the Polypodiaceae.
Amer. Fern J. 56: 113–119.
Swofford, D. L. 2000. PAUP*: Phylogenetic Analysis using
Parsimony (* and other methods), version 4. Sinauer
Associates, Sunderland.
Tejero-Díez, J. D. & Pacheco, L. 2004. Taxa nuevos, nomenclatura, redefinición y distribución de las especies relacionadas con Polypodium colpodes Kunze (Polypodiaceae, Pteridophyta). Acta Bot. Mex. 67: 75–115.
Tryon, A. F. & Lugardon, B. 1991. Spores of the Pteridophyta. Springer-Verlag, New York.
Tryon, R. M . & Stolze, R. G. 1993. Pteridophyta of Peru, Part
V. 18. Aspleniaceae–21. Polypodiaceae. Fieldiana, Bot.,
n.s. 32: 1–190.
Tryon, R. M. & Tryon, A. F. 1982. Ferns and Allied Plants
with Special Reference to Tropical America. Springer,
Berlin.
Walker, T. G. 1966. A cytotaxonomic survey of the pteridophytes of Jamaica. Trans. Roy. Soc. Edinburgh 66: 169–237.
Walker, T. G. 1985. Cytotaxonomic studies of the ferns of
Trinidad. 2. The cytology and taxonomic implications.
Bull. Brit. Mus. (Nat. Hist.), Bot. 13: 149–249.
Weatherby, C. A. 1939. The group of Polypodium polypodioides. Contr. Gray Herb. 124: 22–35.
Weatherby, C. A. 1947. Polypodium lepidopteris and its relatives in Brazil. Contr. Gray Herb. 165:76–82.
Wendt, T. 1980. Notes on some Pleopeltis and Polypodium
species of the Chihuahuan Desert Region. Amer. Fern J.
70: 5–11.
Windham, M. D. 1993. New taxa and nomenclatural changes
in the North American fern flora. Contr. Univ. Michigan
Herb. 19: 31–61.
Appendix 1. Voucher information and GenBank accession numbers given for samples of Serpocaulon used in this
study.
Species, origin, voucher, GenBank accession no. (rbcL, rps4, trnLF).
S. appressum, Bolivia, Jimenez 862 (LPB), DQ151905, DQ151930, DQ151957; S. attenuatum, Nicaragua, Moreno 10406 (UC),
DQ151912, DQ151937, DQ151964; S. crystalloneuron, Bolivia, Jimenez 1109 (LPB), DQ151906, DQ151931, DQ151958; S. crystalloneuron, Bolivia, Jimenez 1176 (LPB), DQ151907, DQ151932, DQ151959; S. dissimile, Ecuador, Smith 2852 (UC), DQ151908,
DQ151933, DQ151960; S. eleutherophlebium, Ecuador, Smith 2877 (UC), AY 362601, AY362673, DQ151983; S. fraxinifolium, Bolivia,
Jimenez 696 (UC), DQ151909, DQ151934, DQ151961; S. giganteum, Bolivia, Jimenez 1035 (UC), DQ151910, DQ151935, DQ151962;
S. gilliesii, Bolivia, Ehrich 314 (UC), DQ151911, DQ151936, DQ151937; S. intricatum, Bolivia, Jimenez 694 (UC), DQ151919,
DQ151944, DQ151967; S. latipes (intricatum), Bolivia, Jimenez 1324 (LPB), DQ151915, DQ151940, DQ151971; S. lasiopus, Bolivia,
Lewis 35186 (UC), DQ151913, DQ151938, DQ151965; S. latipes, Bolivia, Bach 1305 (LPB), DQ151914, DQ151939, DQ151966; S.
latissimum, Bolivia, Jimenez 813 (UC), DQ151916, DQ151941, DQ151968; S. levigatum, Bolivia, Jimenez 756 (UC), DQ151917,
DQ151942, DQ151969; S. maritimum, cult. Alford, Smith s.n. (UC), DQ151918, DQ151943, DQ151970; S. patentissimum, Ecuador,
Smith 2829 (UC), AY362602, AY362674, -; S. ptilorhizon, Bolivia, Jimenez 1102 (UC), DQ151920, DQ151945, DQ151972; S. richardii,
Bolivia, Jimenez 1986 (UC), DQ227291, DQ151929, DQ151956; S. richardii, Ecuador, Moran 6258 (NY), AY362593, AY362666, -; S.
sessilifolium, Bolivia, Jimenez 755 (LPB), DQ151923, DQ151948, DQ151975; S. sessilifolium, Bolivia, Jimenez 806 (LPB), -,
DQ151951, DQ151978; S. sessilifolium, Bolivia, Jimenez 976 (UC), DQ151924, DQ151949, DQ151976; S. sessilifolium, Bolivia,
Jimenez 1034 (LPB), -, DQ151950, DQ151977; S. subandinum, Peru, Hutchison & Wright 5872 (UC), DQ151922, DQ151947,
DQ151974; S. subandinum, Ecuador, Moran 6858 (NY), DQ151921, DQ151946, DQ151973; S. silvulae, Bolivia, Jimenez 1093 (LPB),
DQ151925, DQ151952, DQ151979; S. triseriale, Bolivia, Jimenez 1994 (UC), DQ151926, DQ151953, DQ151980; S. vacillans, Brazil,
Mexia 5856a (UC), DQ151927, DQ151954, DQ151981; S. wagneri, Venezuela, Smith 1171 (UC), DQ151928`, DQ151955, DQ151982.
930
55 (4) • November 2006: Electronic supplement
Smith & al. • Serpocaulon, a new fern genus
Appendix 2. Synonyms referable to species of Serpocaulon (basionyms only). Names included herein are largely on the
basis of descriptions (original and other) and circumscriptions adopted by Lellinger (1989), Hensen (1990), and a few
other sources, as well as provenance of the type and any original illustrations.
Goniophlebium acuminatum Fée, Mém., Foug. 11: 68, pl. 19. 1866. = Serpocaulon sessilifolium (Desv.) A.R. Sm. (fide Hensen, 1990).
Goniophlebium arcuatum Fée, Mém. Foug. 5: 255. 1852. = Serpocaulon loriceum (L.) A.R. Sm. (fide Hensen, 1990).
Goniophlebium chondrocheilon Fée, Mém. Foug. 8: 92. 1857. = Serpocaulon eleutherophlebium (Fée) A.R. Sm. (fide Hensen, 1990).
Goniophlebium deflexum T. Moore & Houlst., Gard. Mag. Bot. 3: 61. 1851. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Lellinger,
1989).
Goniophlebium demissum Fée, Crypt. Vasc. Brésil 2: 63. 1872. = Serpocaulon catharinae (Langsd. & Fisch.) A.R. Sm. (fide Hensen, 1990).
Goniophlebium elatum Fée, Mém. Foug. 5: 256. 1852. = Serpocaulon dissimile (L.) A.R. Sm. (fide Hensen, 1990).
Goniophlebium excelsior Fée, Crypt. Vasc. Brésil 1: 244, pl. 77. 1869. = Serpocaulon meniscifolium (Langsd. & Fisch.) A.R. Sm.
Goniophlebium gauthieri Fée, Crypt. Vasc. Brésil 1: 112, t. 34, f. 3. 1869. = Serpocaulon meniscifolium (Langsd. & Fisch.) A.R. Sm. (fide
Hensen, 1990).
Goniophlebium grammitoides Fée, Crypt. Vasc. Brésil 1: 110, pl. 34. 1869. = Serpocaulon vacillans (Link) A.R. Sm.
Goniophlebium haenkei C. Presl, Tent. pterid. 186, pl. 7. 1836. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Hensen, 1990).
Goniophlebium intermedium Fée, Mém. Foug. 11: 69, t. 18, f. 3. 1866. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989).
Goniophlebium invertens Fée, Mém. Foug. 9: 25. 1857. = Serpocaulon falcaria (Kunze) A.R. Sm. (fide Hensen, 1990).
Goniophlebium pectinans Fée, Crypt. vasc. Brésil 1: 109, pl. 34. 1869. = Serpocaulon catharinae (Langsd. & Fisch.) A.R. Sm. (fide Hensen,
1990).
Goniophlebium pectinatum J. Sm., in Seemann, Bot. Voy. Herald 230. 1854. (nom. illeg., non Goniophlebium pectinatum (L.) J. Sm., 1841,
which is Pecluma pectinata (L.) M. G. Price) = Serpocaulon wagneri (Mett.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Goniophlebium pictum Fée, Crypt. Vasc. Brésil 1: 244. 1869. ≡ Polypodium pictum (Fée) Brade, Arq. Inst. Biol. Veg. 1: 228. 1935, non P.
pictum (T. Moore) Baker ≡ Polypodium limbatum Brade, Arq. Jard. Bot. Rio de Janeiro 11: 30. 1951. = Serpocaulon catharinae (Langsd.
& Fisch.) A.R. Sm. (fide Hensen, 1990).
Polypodium adnatum Kunze ex Klotzsch var. glaucescens Mille, Revista Col. Nac. Vicente Rocafuerte 9: 208. 1927. = Serpocaulon giganteum (Desv.) A.R. Sm. (fide Lellinger, 1989).
Polypodium albopunctatum Raddi, Opusc. Sci. 3: 287. 1819. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium andinum H. Karst., Fl. Columb. 1: 171, pl. 85. 1861 (non Hook., 1860). = Serpocaulon sessilifolium (Desv.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium argyrolepis Sodiro, Crypt. vasc. quit. 355. 1893. = Serpocaulon lasiopus (Klotzsch) A.R. Sm. (fide Hensen, 1990).
Polypodium articulatum Desv., Mém. Soc. Linn. Paris 6: 236. 1827 (non P. articulatum (Sw.) Juss. ex Poir., 1804, which is Oleandra articulata (Sw.) C. Presl) = Serpocaulon caceresii (Sodiro) A.R. Sm. (fide Hensen, 1990).
Polypodium beyerianum Rosenst., Repert. Spec. Nov. Regni Veg. 22: 17. 1925. = Serpocaulon loriceum (L.) A.R. Sm. (fide Lellinger, 1989;
but for a different opinion, see Hensen, 1990, who placed it in synonymy under Polypodium maritimum Hieron.).
Polypodium brasiliense Poir., in Lam., Encycl. 5: 525. 1804. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
= Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989).
Polypodium brasiliense Poir. var. pleiosorum Rosenst. ex Hassl., Treb. Inst. Bot. Farm. Buenos Aires 45: 71. 1928. = Serpocaulon triseriale
(Sw.) A.R. Sm. (vide Lellinger, 1989).
Polypodium campylopodum Klotzsch, Linnaea 20: 395. 1847. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium catharinae Langsd. & Fisch. forma aurita Rosenst., Hedwigia 46: 142. 1906. = Serpocaulon catharinae (Langsd. & Fisch.) A.R.
Sm.
Polypodium catharinae Langsd. & Fisch. forma bipinnatifida Rosenst., Hedwigia 46: 142. 1906. = Serpocaulon catharinae (Langsd. &
Fisch.) A.R. Sm.
Polypodium chartaceum Baker, J. Bot. 15: 166. 1877. = Serpocaulon loriceum (L.) A.R. Sm., s.l. (fide Lellinger, 1989).
Polypodium chnoodes Spreng., Neue Entd. 3: 6. 1822. = Serpocaulon dissimile (L.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium chnoodes Spreng. var. minus H. Christ, Bull. Herb. Boissier, sér. 2, 6: 49. 1906. = Serpocaulon dissimile (L.) A.R. Sm. (fide
Lellinger, 1989).
Polypodium costaricense H. Christ, Bull. Herb. Boissier 4: 660. 1896. = Serpocaulon wagneri (Mett.) A.R. Sm. (fide Lellinger, 1989; Hensen,
1990)
Polypodium cymatodes Kunze, Linnaea 23: 277, 317. 1850 = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Lellinger, 1989).
Polypodium deflexum Houlst. & T. Moore, Gard. Mag. Bot. 3: 60. 1851. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Hensen, 1990).
Polypodium distans Raddi, Pl. Bras. Nov. Gen. 1: 21, pl. 31. 1825 (non Kaulf., 1824). = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide
Lellinger, 1989, Hensen, 1990).
Polypodium elatius Schrad., Gött. Gel. Anz. 1824: 868. 1824. = Serpocaulon meniscifolium (Langsd. & Fisch.) A.R. Sm. (fide Lellinger,
1989; Hensen, 1990).
Polypodium elegans Cav. ex Sw., Syn. fil. 35. 1806 (non Poir., 1804). = Serpocaulon loriceum (L.) A.R. Sm., s.l. (fide Lellinger, 1989).
Polypodium fluminense Vell., Arq. Mus. Nac. Rio de Janeiro 5: 447. 1881. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Hensen, 1990).
Polypodium fraxinifolium Jacq. var. fraxinellum H. Christ, Bull. Herb. Boissier, sér. 2, 5: 5. 1905. = Serpocaulon fraxinifolium (Jacq.) A.R.
Sm. (fide Lellinger, 1989).
Polypodium fraxinifolium Jacq. subsp. articulatum H. Christ, Bull. Herb. Boissier, sér. 2, 6: 49. 1906 = Serpocaulon giganteum (Desv.) A.R.
Sm. (fide Lellinger, 1989).
Polypodium fraxinifolium Jacq. subsp. luridum H. Christ, Bull. Herb. Boissier, sér. 2, 6: 48. 1906 = Serpocaulon giganteum (Desv.) A.R. Sm.
(fide Lellinger, 1989).
Polypodium gladiatum Kunze, Linnaea 9: 45. 1834 (non Vell., 1827) ≡ Polypodium ampliatum Maxon, Contr. U.S. Natl. Herb. 10: 492. 1908.
= Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium glandulosissimum Brade, Arq. Inst. Biol. Veg. 1: 230. 1935. = Serpocaulon catharinae (Langsd. & Fisch.) A.R. Sm. (fide
Hensen, 1990).
1
Smith & al. • Serpocaulon, a new fern genus
55 (4) • November 2006: Electronic supplement
Appendix 2 (continued).
Polypodium glaucophyllum Kunze ex Klotzsch, Linnaea 20: 393. 1847. = Serpocaulon levigatum (Cav.) A.R. Sm. (fide Lellinger, 1989;
Hensen, 1990).
Polypodium glaucum Raddi, Pl. Bras. Nov. Gen. 20, pl. 29. 1825 (non Thunb., 1784) ≡ Chrysopteris raddiana Fée, Crypt. vasc. Brésil 1: 120.
1869. = Serpocaulon catharinae (Langsd. & Fisch.) A.R. Sm. (fide Hensen, 1990).
Polypodium harpeodes Link., Hort. berol. 2: 97. 1833. = Serpocaulon vacillans (Link) A.R. Sm. (fide Hensen, 1990, who first synonymized
P. harpeodes under P. vacillans).
Polyhpodium hassleri H. Christ in Hassler, Bull. Herb. Boissier, sér. 2, 7: 923. 1907. = Serpocaulon vacillans (Link) A.R. Sm.
Polypodium hirsutulum Raddi, Pl. bras. nov. gen. 1: 21, pl. 29. 1825. = Serpocaulon meniscifolium (Langsd. & Fisch.) A.R. Sm. (fide Hensen,
1990).
Polypodium kuhnii E. Fourn., Bull. Soc. Bot. France 19: 251. 1872. = Serpocaulon attenuatum (Humb. & Bonpl. ex Willd.) A.R. Sm.
Polypodium laetum Raddi, Opusc. Sci. 3: 287. 1819 (non Salisb., 1796) = Serpocaulon latipes (Langsd. & Fisch.) A.R. Sm. (fide Hensen,
1990).
Polypodium longifolium C. Presl, Delic. prag. 1: 167. 1822 (non Cav., 1802). ≡ Polypodium preslianum Spreng., Syst. Veg., ed. 4, index.
1828. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium loriceum L. forma duplosorum Domin, Rozpr. Král. Ceské Spolecn. Nauk, Tr. Mat.-Prir. 2[Pterid. Dominica]: 130. 1929, as
“duplisora”. = Serpocaulon loriceum (L.) A.R. Sm., s.l. (fide Lellinger, 1989).
Polypodium loriceum L. var. heterolepis Sodiro, Anales Univ. Centr. Ecuador 11(72): 28 (Crypt. vasc. quit. 352). 1894. = Serpocaulon
loriceum (L.) A.R. Sm., s.l. (fide Lellinger, 1989).
Polypodium loriceum L. var. obscurum Rosenst., Repert. Spec. Nov. Regni Veg. 6: 308. 1909, as “obscura” = Serpocaulon loriceum (L.) A.R.
Sm., s.l. (fide Lellinger, 1989).
Polypodium loriceum L. var. oligomerum H. Christ, Bull. Soc. Roy. Bot. Belgique 35, Mém. 221. 1896. = Serpocaulon loriceum (L.) A.R.
Sm., s.l. (fide Lellinger, 1989).
Polypodium loriceum L. var. squamuligera Rosenst., Repert. Spec. Nov. Regni Veg. 6: 308. 1909. = Serpocaulon loriceum (L.) A.R. Sm., s.l.
(fide Lellinger, 1989).
Polypodium lucens Schrad., Gött. Gel. Anz. 1824: 868. 1824. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium martii Colla, Herb. pedem. 6: 230. 1836. = Serpocaulon vacillans (Link) A.R. Sm. (fide Hensen, 1990).
Polypodium mindense Sodiro, Crypt. vasc. quit. 348. 1893. = Serpocaulon eleutherophlebium (Fée) A.R. Sm. (fide Hensen, 1990).
Polypodium mosenii C. Chr., Bot. Tiddskr. 25: 78. 1902. = Serpocaulon meniscifolium (Langsd. & Fisch.) A.R. Sm. (fide Hensen, 1990).
Polypodium mutabile Kunze, Linnaea 9: 46. 1834. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium neriifolium Schkuhr, 24. Kl. Linn. Pfl.-Syst. 1: 14, t. 15. 1804. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989;
Hensen, 1990).
Polypodium neriifolium Schkuhr var. acuminatissimum Kuntze, Revis. gen. pl. 2: 819. 1891. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide
Lellinger, 1989; holotype NY!).
Polypodium neriifolium Schkuhr var. heterophyllum Kuntze, Revis. gen. pl. 2: 819. 1891. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; holotype NY!).
Polypodium ornatum Klotzsch, Linnaea 20: 396. 1847. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Hensen, 1990).
Polypodium palma Vell., Arq. Mus. Nac. Rio de Janeiro 5: 447. 1881. = Serpocaulon meniscifolium (Langsd. & Fisch.) A.R. Sm. (fide
Hensen, 1990).
Polypodium preslianum var. immersum Rosenst., Repert. Spec. Nov. Regni Veg. 6: 314. 1909. (as “immersa”) = Serpocaulon triseriale (Sw.)
A.R. Sm. (fide Lellinger, 1989).
Polypodium pseudofraternum A.C. Sm., Bull. Torrey Bot. Club 58: 307. 1931. = Serpocaulon sessilifolium (Desv.) A.R. Sm. (fide Lellinger,
1989; Hensen, 1990; holotype NY!).
Polypodium punctulatum Hook., Icon. pl., pl. 720. 1845 (non Poir., 1804). = Serpocaulon subandinum (Sodiro) A.R. Sm. (fide Hensen, 1990).
Polypodium pycnosorum Link, Fil. spec. 128. 1841. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Hensen, 1990).
Polypodium ramosum Loddiges ex Link, Hort. berol. 2: 97. 1833. = Serpocaulon loriceum (L.) A.R. Sm., s.l. (fide Lellinger, 1989).
Polypodium remotum Baker, Ann. Bot. (Oxford) 5: 470. 1891 (non Desv., 1827). ≡ Polypodium uniseriale C. Chr., Index fil. 527. 1906. =
Serpocaulon sessilifolium (Desv.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium retrofractum Desv., Mém. Soc. Linn. Paris 6: 237. 1827. = Serpocaulon dissimile (L.) A.R. Sm. (fide Lellinger, 1989; Hensen,
1990).
Polypodium rhizocaulon Willd., Sp. pl., ed. 4, 5: 196. 1810. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Lellinger, 1989).
Polypodium rimbachii Sodiro, Crypt. vasc. quit. 356. 1893. = Serpocaulon sessilifolium (Desv.) A.R. Sm. (fide Hensen, 1990).
Polypodium rupincolum Brade, Arq. Inst. Biol. Veg. 1: 230. 1935. = Serpocaulon catharinae (Langsd. & Fisch.) A.R. Sm. (fide Hensen,
1990).
Polypodium scutulatum Sodiro, Anales Univ. Centr. Ecuador 22: 169. 1908. = Serpocaulon fraxinifolium (Jacq.) A.R. Sm. (fide Hensen,
1990).
Polypodium sessilifolium Desv. var. papallactense Mille, Revista Col. Nac. Vicente Rocafuerte 9: 211. 1927. = Serpocaulon sessilifolium
(Desv.) A.R. Sm. (fide Lellinger, 1989).
Polypodium subalatum Klotzsch, Linnaea 20: 394. 1847. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Hensen, 1990).
Polypodium subviride Lellinger, Proc. Biol. Soc. Wash. 98: 389, f. 17. 1985. = Serpocaulon loriciforme (Rosenst.) A.R. Sm.
Polypodium surucuchense Hook., Icon. pl. 1: t. 69. 1837. = Serpocaulon sessilifolium (Desv.) A.R. Sm. (fide Hensen, 1990)
Polypodium vagans Mett., Ann. Sci. Nat., Bot., sér. 5, 2: 255. 1864. = Serpocaulon eleutherophlebium (Fée) A.R. Sm. (fide Hensen, 1990).
Polypodium variolatum Willd., Sp. pl., ed. 4, 5: 192. 1810. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Lellinger, 1989; Hensen, 1990).
Polypodium wiesbaueri Sodiro, Recens. Crypt. vasc. quit. 65. 1883. = Serpocaulon eleutherophlebium (Fée) A.R. Sm. (fide Hensen, 1990).
Polypodium xiphophoron Kunze ex Mett., Abh. Senckenberg. Naturf. Ges. 2: 73. 1856. = Serpocaulon triseriale (Sw.) A.R. Sm. (fide Hensen, 1990).
2