DNA amplification and sequencing

Cultures used in this study were obtained from the Centraalbureau voor Schimmelcultures in the Netherlands (CBS). Fungal isolates and DNA extraction isolates were on PDA and MEA, and total genomic DNA extracted from mycelia following the protocols as outlined by Shenoy et al. (2007, 2010). DNA amplification and sequencing were performed following the protocol of Zhang et al. (2009).

Genus included in Sympoventuriaceae

Multigene phylogenetic analysis in this study indicated that species of Venturiales are subdivided into two groups which represent two familial clades, i.e. Sympoventuriaceae and Venturiaceae. Sympoventuriaceae is represented by Sympoventuria, and can be distinguished from species of Venturiales by its saprobic life style, presence of pseudoparaphyses, and hyaline, symmetrical ascospores.

Sympoventuria Crous & Seifert, Fungal Divers 25: 31 (2007).

Generic description:

Habitat saprobic on leaf litter. Ascomata subglobose, immersed, black, inconspicuous, papillate, ostiolate. Pseudoparaphyses hyaline, septate, constricted at septa, anastomosing, extending above the asci. Asci hyaline, subcylindrical, stipitate, 8-spored. Ascospores hyaline, fusoid-ellipsoidal, constricted at median septum (from Crous et al. 2007b).

Anamorph reported for genus: Sympodiella-like.

Type species:

Sympoventuria capensis Crous & Seifert, Fungal Divers 25: 32 (2007).

Anamorph: Sympodiella-like.

Note: The small-sized immersed ascomata agree with Venturia sensu stricto, but the persistent pseudoparaphyses, saprobic life style, hyaline, 1-septate, symmetric ascospores and subcylindrical asci of Sympoventuria capensis differ from those of Venturia sensu stricto (Crous et al. 2007b; Sivanesan 1977). DNA based phylogenies support the placement of Sympoventuria within Venturiales, but not Venturiaceae (Crous et al. 2007b, Fig. 1). Currently, only one monotypic ascomycetous genus, Sympoventuria, is included in Sympoventuriaceae, while the anamorphic genus Veronaeopsis and a clade containing “Fusicladium pini” and “F. intermedium” may represent distinct genera.

Venturiaceae E. Müll. & Arx ex M.E. Barr, Mycologia 71: 947 (1979). emend.

Habitat saprobic or parasitic on leaves or stems of dicotyledons, rarely on monocotyledons. With or without ascostroma. Ascomata immersed, erumpent to superficial, scattered or gregarious, sometimes composed of a well-developed subiculum, globose, subglobose, with or without setae around papilla, ostiolate. Hamathecium of narrowly cellular pseudoparaphyses, mostly evanescent and rarely persistent. Asci 8-spored, bitunicate, fissitunicate, usually obclavate to obpyriform, rarely cylindrical, usually apedicellate. Ascospores hyaline, yellowish, light greenish olivaceous to brown, 1-septate, symmetrical, asymmetrical or apiosporous.

Anamorphs: Fusicladium, Pollaccia, Spilocaea and ? Pseudocladosporium-like.

Type genus: Venturia Sacc.

Genera included in Venturiaceae

Based on both morphological, ecological comparisons and limited molecular phylogenetic analysis, eight genera are included within Venturiaceae, viz. Acantharia, Apiosporina, Dibotryon, Caproventuria, Coleroa, Pseudoparodiella, Venturia and Metacoleroa. However further molecular analysis is necessary to confirm the inclusion of some genera, such as Acantharia, Coleroa and Pseudoparodiella.

Key to the genera of Venturiaceae

Acantharia Theiss. & Syd., Annls mycol. 16: 15 (1918).

= Zeuctomorpha Sivan., P.M. Kirk & Govindu, Bitunicate Ascomycetes and their Anamorphs (Vaduz): 572 (1984).

Generic description:

Habitat parasitic or saprobic. Ascomata small-sized, gregarious, superficial, globose, subglobose to ovate, usually cupulate when dry, thickly clothed with opaque, black setae. Peridium comprising two-strata of cell types. Hamathecium of cellular pseudoparaphyses, evanescent in mature ascomata. Asci 8-spored, bitunicate, fissitunicate, obclavate, apedicellate. Ascospores obliquely uniseriate and partially overlapping at the apex and biseriate at the base, subcylindrical to ellipsoidal, with broadly to narrowly rounded or tapered ends, brown to dark brown with a greenish tint, 1-septate, constricted at the septum, the upper cell often shorter and broader than the lower one, smooth-walled.

Anamorph reported for genus: Fusicladium-like, Stigmina (Sivanesan 1984b).

Type species:

Acantharia echinata (Ellis & Everh.) Theiss. & Syd., Annls mycol. 16: 15 (1918). (Fig. 3)

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Fig. 3

Acantharia echinata (from NY, holotype)

a, b. Superficial ascoma gregarious on the substrate surface. c. Section of an ascoma. Note large heavily pigmented thick-walled cells. d–f. Obclavate asci. g–i. Released ascospores. Scale bars: a=5 mm, b=0.5 mm, c=50 μm, d–i=10 μm

≡ Dimerosporium echinatum Ellis & Everh., Erythea 1: 145 (1893).

Ascomata 70–157 μm high×115–186 μm diam., gregarious, forming densely crowded, orbicular patches of 3–5 mm diam., superficial, globose, subglobose to ovate, cupulate when dry, thickly clothed with opaque, black setae, 70–110 μm long, 5–7 μm thick at the base (Fig. 3a, b). Peridium 20–27.5 μm wide, up to 40 μm thick near the base, comprising two-strata of cell types, outer layer composed of 1–3 layers of large heavily pigmented thick-walled cells of textura angularis, cells 8–13 μm diam., cell wall 1–4 μm thick, basal cells smaller and walls thicker; inner layer composed of lightly pigmented cells of textura angularis, up to 3×12 μm diam. (Fig. 3c). Hamathecium of cellular pseudoparaphyses, 2–4 μm broad, embedded in mucilage, evanescent in mature ascomata. Asci 65–100×14–25 μm (=80.8×19.6 μm, n=10), 8-spored, bitunicate, fissitunicate, obclavate, without pedicel (Fig. 3d–f). Ascospores 17.5–22.5×9–12.5 μm (=20.3×9.8 μm, n=10), obliquely uniseriate and partially overlapping at the apex and biseriate at centre or sometimes at the base, broadly cylindrical to ellipsoidal with broadly to narrowly rounded or tapered ends, brown to dark brown with greenish tint, 1-septate, constricted at the septum, the upper cell often shorter and broader than the lower one, smooth-walled (Fig. 3g–i).

Material examined: USA: California, Amador County, Jackson, on living leaves of Quercus chrysolepis, leg. Geo. Hansen, com. Marshall A. Howe (NY, holotype).

Anamorph: Fusicladium-like sp. (Sivanesan 1984b).

Note: The folicolous habitat, superficial, setose ascomata, evanescent pseudoparaphyses, obclavate asci, and 1-septate, brown and constricted ascospores are typical of Venturiaceae.

Acantharia arecae (Sivan., P.M. Kirk & Govindu) Yin. Zhang & K.D. Hyde, comb. nov.

≡ Zeuctomorpha arecae Sivan., P.M. Kirk & Govindu, in Sivanesan, Bitunicate Ascomycetes and their Anamorphs (Vaduz): 572 (1984).

Material examined: INDIA: Shimogee, on Areca catechu L. leaf, 1 Nov. 1979, H.C. Govindu (IMI 246067, holotype of Zeuctomorpha arecae).

Anamorph: Acroconidiellina arecae (Sivanesan 1984a).

Note: The small-sized setose ascomata, obclavate to obpyriform asci, asymmetrical pigmented ascospores of Zeuctomorpha point to Acantharia (Sivanesan 1984b). The anamorphic state of Zeuctomorpha (Acroconidiellina arecae) is also comparable with that of Acantharia (Fusicladium-like). Thus we treat Zeuctomorpha arecae here as a synonym of Acantharia arecae. Similarly, Zeuctomorpha is treated as a synonym of Acantharia. Zeuctomorpha arecae however, differs in having a thickened ascal apex with a distinct ocular chamber while its occurrence on palms is also contradictory to the understanding of the Venturiaceae (Zhang et al. 2012). Fresh collections and molecular study are needed to confirm whether these genera are synonymous and whether Acantharia should be included in Venturiaceae.

Apiosporina Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. I 119: 439 (1910).

= Dibotryon Theiss. & Syd., Annls mycol.13: 663 (1915).

Generic description:

Habitat parasitic (or saprobic?) on leaves or stems of dicotyledons. Ascomata small-sized, gregarious, superficial, globose to subglobose, developing on a hyphal mass, easily removable from the substrate, small papillate and ostiolate. Peridium thin, composed of several layers of heavily pigmented thick-walled cells of textura angularis. Hamathecium of rare, septate, pseudoparaphyses. Asci 8-spored, bitunicate to narrowly obclavate, cylindrical, with a short, thick, furcate or knob-like pedicel or pedicel lacking. Ascospores biseriate and partially overlapping, ovoid to narrowly ovoid, hyaline to pale brown, apiosporous, 1-septate near the lower end, barely constricted at the septum, smooth-walled.

Anamorph reported for genus: Cladosporium sp. or Fusicladium sp. (Sivanesan 1984a).

Type species:

Apiosporina collinsii (Schwein.) Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. I 119: 439 [47 repr.] (1910). (Fig. 4)

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Fig. 4

Apiosporina collinsii ((K(M):158702, ex herb. Broome)

a. Ascomata gregarious on the substrate surface. b. Squash mounts with a large number of asci. c. Cylindrical 8-spored asci. d. Released ascospores. Scale bars: a=0.5 mm, b, c=10 μm, d=5 μm

≡ Sphaeria collinsii Schwein., Trans. Am. phil. Soc. 4: 211 (1832).

Ascomata 140–172 μm diam., gregarious, superficial, globose to subglobose, developing on a hyphal mass, easily removable from the substrate, black with rough and shiny surface, papillate small and ostiolate (Fig. 4a). Peridium 20–33 μm wide, composed of 3–4 layers of heavily pigmented thick-walled cells of textura angularis, cells 5–10 μm diam., cell wall up to 2.5 μm thick, the innermost layer cell-wall thinner. Hamathecium of rare, septate, 4–6 μm broad pseudoparaphyses. Asci 63–77×8–10 μm (= 70.9×9.3 μm, n=10), 8-spored, bitunicate, fissitunicate dehiscence not observed, cylindrical to narrowly obclavate, with a short, thick, knob-like pedicel or pedicel lacking (Fig. 4b, c). Ascospores 12.5–15×5–6 μm (=13.4× 5.3 μm, n=10), biseriate and partially overlapping, ovoid to narrowly ovoid, hyaline, 1-septate, apiosporous, slightly constricted at the septum, the upper cell often 4–5 times longer and much broader than the lower one, smooth-walled (Fig. 4d).

Material examined: CANADA: Saskatchwan, on leaves of Cotoneaster sp. (K(M):158702, ex herb. Broome).

Anamorph: Cladosporium sp. (Sivanesan 1984a).

Apiosporina morbosa (Schwein.) Arx, Acta bot. neerl. 3: 86 (1954). (Fig. 5)

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Fig. 5

Dibotryon morbosa (PH-01048831, syntype)

a. Ascomata densely gregarious on the substrate surface. b. Section of ascomata. c. Asci in pseudoparaphyses. d. Septate pseudoparaphyses. e. Released apiosporous ascospores. Scale bars: a=0.5 mm, b=100 μm, c, d=10 μm

≡ Dibotryon morbosum (Schwein.) Theiss. & Syd., Annls mycol. 13(5/6): 663 (1915).

≡ Sphaeria morbosa Schwein., Schr. naturf. Ges. Leipzig 1: 40 (1822).

Ascomata densely developing in branches, erumpent and form a swelling up to 1 cm thick, black, hard. Ascomata 160–230 μm high×170–250 μm diam., densely gregarious on the surface of ascostromata, subglobose, triangular or oblong, often flattened on the top, wall black (Fig. 5a, b). Peridium 30–45 μm wide, 1-layered, composed of small heavily pigmented thick-walled cells of textura angularis, cells 3–7 μm diam., cell wall 2–4 μm thick, cells at the base of the ascomata larger, up to 10 μm diam. (Fig. 5b). Hamathecium of dense, 1.5–2(−3) μm broad, septate, branched pseudoparaphyses (Fig. 5d). Asci 68–90×12.5–15 μm (=73×13 μm, n=10), 8-spored, bitunicate, fissitunicate dehiscence not seen, subcylindrical or broadly clavate, with a short, furcate pedicel which is 8–15 μm long, with an inconspicuous ocular chamber (Fig. 5c). Ascospores 15–18(−19)×(5-)6–7.5 μm (=17.4×6.8 μm, n=10), biseriate, clavate, apiosporous, tapered towards the base, apex obtusely rounded, one septate near the lower end, barely constricted at the septum, hyaline to pale brown, smooth-walled (Fig. 5e).

Material examined: USA: Pennsylvania, Bethlehem, in Prunis cultis, Syn. #1416. leg. L.D. von Schweinitz s.n. Det. L.D. von Schweinitz (PH-01048831, 01048832, 01048838, 01048839, 01048840, as Sphaeria morbosa Schw., syntype; PH-01048834).

Anamorph: ?Fusicladium sp. (Sivanesan 1984a).

Note: The anamorphic state of A. collinsii was reported as Cladosporium sp. (Sivanesan 1984a), which was assigned to Fusicladium sensu lato by Braun et al. (2003). A narrow concept of Fusicladium, however, is accepted in this study. Dibotryon had been treated as a synonym of Apiosporina (von Arx and Müller 1975; Barr 1968; Crous et al. 2007a). Although the black knots on branches of Prunis cultis formed by Dibotryon morbosum can be readily distinguished from the black spots on leaves formed by Apiosporina, their congeneric relationship was confirmed by molecular data (Winton et al. 2007, Figs. 1 and ​and22).

Caproventuria U. Braun, Monogr. Cercosporella, Ramularia Allied Genera (Phytopath. Hyphom.) 2: 396 (1998).

Generic description:

Habitat saprobic. Ascomata non-stromatic, subglobose, ampulliform, obpyriform, urceolate, papillate, ostiolate, pseudoparaphysate, membranaceous, dark, setose throughout. Setae dark brown, aseptate, simple or occasionally forked, apex acute, smooth, wall thickened below, but thin-walled towards the apex. Peridium pseudoparenchymatous, composed of angular to rounded, dark brown cells. Asci 8-spored, bitunicate, numerous, subclavate to cylindrical. Ascospores monostichous or distichous, ellipsoidovoid, with a single submedian septum, mostly somewhat constricted at the septum, smooth, yellowish olivaceous (from Braun 1998).

Anamorph reported for genus: Pseudocladosporium (Braun et al. 2003).

Type species:

Caproventuria hanliniana (U. Braun & Feiler) U. Braun, Monogr. Cercosporella, Ramularia Allied Genera (Phytopath. Hyphom.) 2: 396 (1998).

≡ Capronia hanliniana U. Braun & Feiler, Microbiol. Res. 150: 90 (1995).

Anamorph: Pseudocladosporium brevicatenatum (U. Braun & Feiler) U. Braun 1998.

Note: Braun (1998) treated Caproventuria as separate genus from Venturia based on its saprobic life style and Pseudocladosporium anamorphic state, compared to the parasitic life style and Pollaccia or Spilocaea anamorphic state possessed by Venturia sensu stricto. Crous et al. (2007b), however, treated Pseudocladosporium as a synonym of Fusicladium sensu lato based on the combined LSU and ITS nurDNA sequences comparison, and considered the arrangement of the conidiophores (solitary, fasciculate, sporodochial), the proliferation of conidiogenous cells (sympodial, percurrent) and shape, size as well as formation of conidia (solitary, catenate) to be of little taxonomic value at generic level. This proposal, however, is not supported in this study, as narrow generic concepts of Venturia and Fusicladium are accepted here. In addition, according to our multigene phylogenetic analysis, species of Caproventuria and Tyrannosorus form a unambiguously supported clade separating from the clade Venturia sensu stricto. Based on both the anamorph and molecular phylogeny, Caproventuria is a well defined genus of Venturiaceae.

Coleroa Rabenh., Herb. myc., ed. 1no. 1456 (1850).

Generic description:

Habitat parasitic and saprobic on dicotyledons. Ascomata small-sized, scattered, or in small groups, superficial, globose, subglobose, setae few to numerous, papillate, ostiolate. Peridium thin, composed of lightly pigmented thin-walled cells of textura angularis. Hamathecium ca. 2 μm broad, evanescing. Asci 8-spored, bitunicate, fissitunicate, fusiform to obclavate, with or without pedicel. Ascospores ellipsoidal with broadly to narrowly rounded ends, pale brown with greenish tint, 1-septate, constricted at the septum.

Anamorph reported for genus: none.

Type species:

Coleroa chaetomium (Kunze ex Fr.) Rabenh., Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1:198 (1850). (Fig. 6)

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Fig. 6

Coleroa chaetomium (L11558.38)

a. Ascomata scattered on the substrate surface. b. Section of an ascoma. c, d. Somewhat obclavate, 8-spored asci without pedicel. e. Released ascospores. Scale bars: a= 0.5 mm, b=50 μm, c, d=10 μm, e=5 μm

≡ Dothidea chaetomium Kunze ex Fr., Syst. mycol. (Lundae) 2: 563 (1823).

Ascomata 130–170 μm high×80–130(−160) μm diam., scattered, or in small groups of 2–4 with confluent peridium, superficial, produced on thin subcuticular stroma, globose, subglobose, wall black, setae few to numerous, septate or non-septate, variable in length, up to 130 μm, 5–7 μm thick near the base, reddish-brown, paler at the apex, ostiole short (Fig. 6a). Peridium 15–25 μm wide, composed of lightly pigmented thin-walled cells of textura angularis, cells 5–12 μm diam., cell wall <1 μm thick (Fig. 6b). Hamathecium ca. 2 μm broad, cellular, septate, usually evanescing in mature ascomata. Asci 45–58×12–16 μm (=53.3× 13.5 μm, n=10), 8-spored, bitunicate, fissitunicate, fusiform to obclavate, with or without pedicel, with an inconspicuous ocular chamber (Fig. 6c, d). Ascospores 11–14(−17)×5.5–6 μm (=13.2×5.9 μm, n=10), obliquely uniseriate and partially overlapping to biseriate in centre, ellipsoidal with broadly to narrowly rounded ends, pale brown with greenish tint, 1-septate, constricted at the septum, the upper cell often longer and broader than the lower one, verrucose (Fig. 6e).

Material examined: ITALY: Treviso, Bosco Montello, on the leaf surface of Rubus caesius, Sept. 1876. P.A. Saccardo (L11558.30 as Venturia kunzei Sacc.); ROMANIA: Plopeni, on Rubus caesius L., Aug. 1971, leg. & det. G. Negrean (L11558.4); on Rubus idaeus, leg. J. Smarods, 18 Oct. 1942 (L11558.16); L11558.39, as Dothidea chaetomium; on leaves of Rubus sp., leg. Kretzschmar (L11558.38, as Phacidium rubi Fries); 9 Oct. 1903, leg. G. Oertel. (L11558.3).

Anamorph: none reported.

Note: The scattered, setose ascomata, deliquescing pseudoparaphyses, fusoid to obclavate asci and the 1-septate, constricted ascospores of Coleroa chaetomium suggest an affinity to Venturiaceae.

Pseudoparodiella F. Stevens, Illinois Biol. Monogr. (Urbana) 11: 166 (1927).

Generic description:

Habitat parasitic on leaf surface of dicotyledonous plants. Ascomata small-sized, scattered or gregarious, superficial, globose. Peridium thin, composed of a few layers of lightly pigmented thin-walled cells of textura angularis. Hamathecium of rare, 2–3 μm broad pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate dehiscence not observed, obclavate, with a short, thick, knob-like pedicel, with an ocular chamber. Ascospores biseriate and partially overlapping, broadly fusoid to ellipsoidal with broadly to narrowly rounded ends, olivaceous to pale brown, 1-septate, constricted at the septum, the upper cell slightly longer and broader than the lower one.

Anamorph reported for genus: none.

Type species:

Pseudoparodiella vernoniae F. Stevens, Illinois Biol. Monogr. (Urbana) 11: 166 (1927). (Fig. 7)

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Fig. 7

Pseudoparodiella vernoniae (K(M):154549, holotype)

a. Setose ascomata scattered on the substrate surface. b. Section of an ascoma c. Squash mounts with two asci. d. Released, 1-septate ascospores. Scale bars: a=200 μm, b=20 μm, c, d=10 μm

Ascomata 80–130 μm diam., scattered or gregarious, superficial, globose, easily removed from the substrate, wall black, apex opening not observed (too small to see clearly) (Fig. 7a). Peridium 10–15 μm wide, composed of 2–3 layers of lightly pigmented thin-walled cells of textura angularis, cells 4–6 μm diam., cell wall 0.5–1 μm thick, up to 2 μm thick at the outer layer (Fig. 7b). Hamathecium of rare, 2–3 μm broad pseudoparaphyses. Asci 55–72×17–22 μm (=62.5×20.3 μm, n=10), 8-spored, bitunicate, fissitunicate dehiscence not observed, obclavate, with a short, thick, knob-like pedicel which is usually less than 10 μm long, with an ocular chamber (Fig. 7c). Ascospores 16–19×6–8 μm (=17×7 μm, n=10), biseriate and partially overlapping, broadly fusoid to ellipsoidal with broadly to narrowly rounded ends, olive pale brown, 1-septate, constricted at the septum, the upper cell slightly longer and broader than the lower one, smooth-walled (Fig. 7d).

Material examined: SPAIN: Peralta, on leaves of Vernonia canescens, 7 Dec. 1923, leg. & det. F.L. Stevens (K(M):154549, holotype).

Anamorph: none reported.

Note: The small-sized ascomata produced on leaves of dicotyledons, rare pseudoparaphyses, obclavate asci, 1-septate olivaceous brown ascospores agree with Venturiaceae.

Metacoleroa Petr., Annls mycol. 25: 332 (1927).

Anamorph reported for genus: none.

Type species:

Metacoleroa dickiei (Berk. & Broome) Petr. [as ‘dieckiei’], Annls mycol. 25: 332 (1927).

≡ Sphaeria dickiei Berk. & Broome, Ann. Mag. nat. Hist., Ser. 2 9: 317 (1852).

Material examined: UK: Carlton House, on leaves of Linnaea borealis, 1827, Richardson (K(M): 143928; syntype).

Anamorph: none reported.

Note: No mature ascoma were found on the specimen examined. Based on DNA sequence analysis, Metacoleroa clustered with Venturia sensu lato, thus was treated as synonym (Crous et al. 2007a). However the phylogeny presented in Crous et al. (2007a) was not well resolved and our analysis did not resolve this either (Fig. 1). This proposal needs further study.

Tyrannosorus Unter. & Malloch, Mycol. Res. 99(8): 910 (1995).

Generic description:

Habitat saprobic. Ascomata solitary, dark brown to black, ovate to pyriform, ostiolate, covered with brown setae. Peridium pseudoparenchymatous. Hamathecium trabeculate pseudoparaphyses. Asci bitunicate, saccate to clavate with a thickened endotunica. Ascospores brown, fusoid, 1-septate, indistinctly striate, each cell with 3–5 elongate germ slits (from Untereiner et al. 1995).

Anamorph reported for genus: Helicodendron (Untereiner et al. 1995).

Type species:

Tyrannosorus pinicola (Petrini & P.J. Fisher) Unter. & Malloch, Mycol. Res. 99(8): 910 (1995).

≡ Capronia pinicola Petrini & P.J. Fisher, Trans. Br. mycol. Soc. 88(1): 68 (1987).

Anamorph: Helicodendron pinicola E. Müll., Petrini, P. J. Fisher, Samuels & Rossman ex Voglmayr & P.J. Fisher, Mycol. Res. 101(9): 1124 (1997).

Note: Tyrannosorus was separated from Capronia and was introduced as a monotypic genus represented by T. pinicola based on its helicosporous anamorph and longitudinally ridged ascospores with multiple germ slits (Untereiner et al. 1995). According to our molecular phylogenetic analysis based on five genes, i.e. nuLSU, nuSSU, RPB1, 2 and TEF1, Caproventuria hanliniana and C. hystrioides together with Tyrannosorus pinicola form a unambiguously supported clade separating from Venturia sensu stricto. Both Tyrannosorus and Caproventuria share setose ascomata, 1-septate, brown or yellowish olivaceous ascospores, which are typical of Venturiaceae. The helicosporous anamorph of Tyrannosorus pinicola (Helicodendron pinicola) is quite different from the Pseudocladosporum anamorph of Caproventuria species. In addition, the indistinctly striate ascospores with germ slits of Tyrannosorus pinicola are also quite different from species of Caproventuria (Braun 1998; Untereiner et al. 1995). Thus here we treat Caproventuria and Tyrannosorus as separate genera of Venturiaceae.

Venturia Sacc., Syll. fung. (Abellini) 1: 586 (1882).

Generic description:

Habitat parasitic on dicotyledonous leaves. Ascomata small-sized, solitary, scattered, or gregarious, initially immersed, becoming erumpent, globose, subglobose, wall black, papillate, ostiolate. Peridium thin, composed of a few layers of pigmented cells of textura angularis. Hamathecium rare, evanescent in mature ascomata. Asci 8-spored (rarely 4-spored), bitunicate, fissitunicate dehiscence unknown, oblong to obclavate, with a short, thick pedicel or pedicel lacking, with an inconspicuous ocular chamber. Ascospores obliquely uniseriate and partially overlapping to biseriate, especially at the base, ellipsoidal, with broadly rounded ends, pale brown, 1-septate, slightly constricted at the septum, the upper cell shorter than the lower one, smooth-walled.

Anamorph reported for genus: Spilocaea, Pollaccia (Barr 1968; Crous et al. 2007a; Sivanesan 1984a).

Type species:

Venturia inaequalis (Cooke) G. Winter, Hedwigia 36: 81 (1897) (Fig. 8)

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Fig. 8

Venturia inaequalis (L 0054534, isotype of Didymosphaeria inaequalis (Cooke) Nissl.)

a. Ascostroma on the surface of substrate. b, c. Ascus. d. Section of the peridium comprising a few layers of texture of angularis cells. e. Decomposing pseudoparaphyses. f, g. Ascospores with one septum. Scale bars: a=0.5 mm, b, c, e – g=10 μm, d=20 μm

≡ Sphaerella inaequalis Cooke, J. Bot. 4: 248 (1866).

Ascomata 90–180 μm high×90–200(−240) μm diam., solitary, scattered, or gregarious, initially immersed, becoming erumpent, globose, subglobose, wall black, ostiolate with a distinct papilla (Fig. 8a). Peridium 20–28 μm wide, 1-layered, composed of (2-)3–4 layers of pigmented cells of textura angularis, cells 5–10 μm diam., cell wall 0.8–1.5 μm thick (Fig. 8d). Hamathecium rare, ca. 2 μm broad, evanescent in mature ascomata (Fig. 8e). Asci (53-) 70–90×9.5–14 μm (=73.5×10.8 μm, n=10), 8-spored (rarely 4-spored), bitunicate, fissitunicate dehiscence not observed, oblong to obclavate, with a short, thick pedicel or pedicel lacking, with an inconspicuous ocular chamber (Fig. 8b, c). Ascospores 13–17×6–8 μm (=14.8×7.2 μm, n=10), obliquely uniseriate and partially overlapping to biseriate, especially at the base, ellipsoidal, with broadly rounded ends, pale brown, 1-septate, slightly constricted at the septum, the upper cell shorter than the lower one (4:5-) 2:3(−1:2), smooth-walled (Fig. 8f, g).

Material examined: CZECH REPUBLIC: Brno (‘Brünn’), on leaves of Sorbus torminalis (Rosaceae). Niessl s.n., Mar. 1913, distributed in Rabenhorst, Fungi Europaei 2663, leg. de Niessl (L 0054534, isotype of Didymosphaeria inaequalis (Cooke) Nissl.).

Anamorph: Spilocaea pomi (Schubert et al. 2003).

Note: A relatively broad concept for Venturia was adopted by Sivanesan (1977), who considered the genus to comprise species having separate or aggregated ascomata with or without stroma, or forming below a blackened clypeus, symmetrical or asymmetrical, olive green, pale brown or dark brown ascospores and being parasitic on leaves or stems of dicotyledons. DNA sequence analysis had indicated that species of Venturia clustered together with Apiosporina collinsii, Caproventuria hanliniana and Metacoleroa dickiei, and thus Caproventuria and Metacoleroa were treated as synonyms of Venturia (Crous et al. 2007a), although their ecological, morphological or anamorphic states are distinct from each other (see the key of genera). This proposal, however, needs further consideration and study. Herein we apply a narrower generic concept for Venturia, which comprises parasitic species closely related to the generic type of Venturia (V. inaequalis).

Other genera included in Venturiales

Based on morphology, the genera Arkoola, Atopospora, Botryostroma, Lasiobotrys, Rhizogene, Trichodothella and Trichodothis may be related to Venturiaceae. Thus we provisionally include them in Venturiaceae, but their ordinal and/or familial status needs confirmation based on DNA sequence data.

Arkoola J. Walker & Stovold, Trans. Br. mycol. Soc. 87: 28 (1986).

Anamorph reported for genus: none.

Type species:

Arkoola nigra J. Walker & Stovold, Trans. Br. mycol. Soc. 87: 29 (1986).

Anamorph: none reported.

Note: The superficial, setose ascomata produced on mycelium and greenish-brown, asymmetrical, thin-walled ascospores fit Venturiaceae well. The large-sized ascomata, cylindrical asci and short pedicels of Arkoola however, differ from other genera of Venturiaceae (Walker and Stovold 1986).

Atopospora Petr., Annls mycol. 23: 100 (1925).

Anamorph reported for genus: ?Didymochora (Sivanesan 1984a).

Type species:

Atopospora betulina (Fr.) Petr., Annls mycol. 23: 101 (1925).

≡ Xyloma betulinum Fr., Observ. mycol. (Havniae) 1: 198 (1815).

Anamorph: ?Didymochora betulina (Sivanesan 1984a).

Note: The multiloculate ascostromata, fusoid asci and lightly pigmented, biseriate, apiosporous ascospores suggest an affinity to Venturiales (Müller and von Arx 1962).

Botryostroma Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 120: 424 [46 repr.] (1911).

Anamorph reported for genus: none.

Type species:

Botryostroma inaequale (G. Winter) Höhn. [as ‘inaequalis’], Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 120: 425 [47 repr.] (1911).

≡ Lizonia inaequalis G. Winter, Hedwigia 22: 261 (1883).

Anamorph: none reported.

Note: The ascomata of Botryostroma inaequale are produced under a clypeus, with numerous persistent pseudoparaphyses among asci. All these characters do not fit Venturiales. However, the obclavate or fusiform asci, lightly pigmented, apiosporous ascospores suggest an affinity to Venturiales (Müller and von Arx 1962).

Lasiobotrys Kunze, in Kunze & Schmidt, Mykologische Hefte (Leipzig) 2: 88 (1823).

Anamorph reported for genus: none.

Type species:

Lasiobotrys lonicerae Kunze, in Fries, Syst. mycol. (Lundae) 2: 88 (1823).

Anamorph: none reported.

Note: The most striking morphological character of Lasiobotrys is its ascomata produced among hyphae under a stromatal disc (forming a “roof-like” structure) (see Müller and von Arx 1962). The apiosporous, lightly pigmented ascospores, subclavate to obclavate asci are comparable with taxa of Venturiales.

Rhizogene Syd. & P. Syd., Annls mycol. 18: 181 (1921) [1920].

Anamorph reported for genus: none.

Type species

Rhizogene symphoricarpi (Syd. & P. Syd.) Syd. & P. Syd., Annls mycol. 18: 181 (1921) [1920].

≡ Lasiobotrys symphoricarpi Syd. & P. Syd., Annls mycol. 16: 244 (1918).

Anamorph: none reported.

Note: Ascomata of Rhizogene symphoricarpi are produced radially around the circumference of the stromatal disc, which is covered with short setae. The subclavate to somewhat obclavate asci and lightly pigmented, submedianly 1-septate ascospores are comparable with Venturiales (Müller and von Arx 1962).

Trichodothella Petr., in Blumer, Ergebn. wiss. Unters. schweiz. NatnParks, N.S. 14: 37 (1946).

Anamorph reported for genus: none.

Type species:

Trichodothella blumeri Petr. ex S. Blumer, Ergebn. Wiss. Unters. Schweiz. Natn Parks, N.S. 14: 37 (1946).

Anamorph: none reported.

Note: Considering the position of ascomata on the ascostromata, Trichodothella is a “transition” genus—the ascomata of which are produced radially around the circumference of the stromatal disc, but under the hyphae around the ascostromata (Müller and von Arx 1962).

Trichodothis Theiss. & Syd., Annls mycol. 12: 176 (1914).

Generic description:

Habitat saprobic or parasitic? on leaf surface of dicotyledonous. Ascostromata medium-sized, solitary, scattered, or in small groups, superficial, multilocular, discoid, with straight or flexuous aggregations of hairs sticking together and forming stellate projections around the ascostroma. Locules small-sized, globose to subglobose, forming one layer within the ascostroma. Peridium one layered, lower peridium composed of light pigmented cells of textura angularis, upper peridium composed of more heavily pigmented thick-walled cells of textura angularis. Hamathecium of dense, cellular pseudoparaphyses, septate, hyaline. Asci 8-spored, bitunicate, fissitunicate dehiscence not observed, saccate, without pedicel. Ascospores 3–4-seriate, broadly ellipsoidal with broadly rounded ends, hyaline and becoming pale brown when old, 1-septate, slightly constricted at the septum.

Anamorphs reported for genus: none.

Type species:

Trichodothis comata (Berk. & Ravenel) Theiss. & Syd., Annls mycol. 12: 176 (1914). (Fig. 9)

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Fig. 9

Trichodothis comata (K (M): 143933, syntype)

a. An flattented ascostroma on the substrate surface. b, c. Section of a partial ascostroma. d, e. Section of a partial peridium comprising a few layers of texture of angularis cells. f. Pseudoparaphyses with immature asci. g. Ascus. h. Released 1-septate ascospore. Scale bars: a=0.5 mm, b, c=100 μm, d–f=50 μm, g, h=20 μm

≡ Asterina comata Berk. & Ravenel, Grevillea 4 (no. 29): 10 (1875).

Ascostromata 72–157 μm high×243–529 μm diam. (excluding the stellate aggregations), solitary, scattered, or in small groups, superficial, multilocular, discoid, with straight or flexuous, septate, dark brown aggregations of hairs sticking together and forming stellate projections around the ascostromata, projections black, cylindrical, 6–8 μm broad. Locules 60–95 μm high×75–115 μm diam., globose to subglobose, forming a single layer within ascostromata, and extending as far as 100–214 μm out of the edge of ascostromata (Fig. 9a, c). Peridium 28–42 μm wide, one layered, lower peridium composed of light pigmented cells of textura angularis, cells 5–9 μm diam., cell wall 1.5–2.5 μm thick, apex cells smaller and walls thicker, upper peridium composed of more heavily pigmented thick-walled cells of textura angularis (Fig. 9b, d, e). Hamathecium of dense, cellular pseudoparaphyses, ca. 2.5–4 μm diam., septate, hyaline (Fig. 9e, f). Asci 55–70×15–22 μm, 8-spored, bitunicate, fissitunicate dehiscence not observed, saccate, without pedicel, ocular chamber not observed (Fig. 9g). Ascospores 14–23×6.5–10.5 μm, 3–4 seriate, broadly ellipsoidal with obtusely rounded ends, hyaline and becoming pale brown when old, 1-septate, slightly constricted at the septum, smooth-walled (Fig. 9h).

Material examined: USA: South Carolina, Santee Canal, on Magnolia grandiflora leaf, 1819; leg. H.W. Ravenel (K(M): 143933, ex herb. Berkeley, syntype).

Anamorph: none reported.

Note: Trichodothis comata is characterized by its ascostromata covered by dark brown hairs, broad pseudoparaphyses, saccate asci and hyaline, 1-septate ascospores (Müller and von Arx 1962, Fig. 9). Trichodothis is most comparable with Lasiobotrys, Rhizogene and Trichodothella, which have ascomata beneath or radially around the circumference of the stromatal disc (Müller and von Arx 1962). All these characters make it difficult to be assigned Trichodothis in a family or even order. Because the morphology of asci and ascospores are most comparable with Venturiales, we questionably accept it in Venturiales, until further molecular phylogenetic result is available.

Ying Zhang would like to thank the Mushroom Research Foundation, Chiang Mai, Thailand for providing her with a post doctoral fellowship for this study. We are grateful to the Directors and Curators of NY, K, L, PH, S for the loan of specimens in their keeping. E.H.C. McKenzie is thanked for his comments on an earlier version of the script. This work was supported by Thailand Research Fund BRG528002. The Global Research Network for Fungal Biology and King Saud University are also thanked for support. Conrad L. Schoch acknowledges support by the Intramural Research Program of the NIH, National Library of Medicine.