Helicomyces paludosa (P. Crouan & H. Crouan), Boonmee & K.D. Hyde, comb. nov.,Index Fungorum number: IF550689.
≡ Nectria paludosa P. Crouan& H. Crouan, Florule du Finistere p. 38. 1867
≡Tubeufia paludosa (P. Crouan & Crouan) Rossman, Mycologia 69(2): 383 (1977)
Saprobic on decorticated or decaying woody and herbaceous substrates, in terrestrial habitats, widespread in temperate to tropical regions. Sexual state: Ascomata (267-)278–297(-312) µm high ´ 180–203 µm diam., superficial, seated on a thin subiculum, uniloculate, subglobose, clavate to obovate, coriaceous, solitary to gregarious, pale brown to reddish-brown, centrally ostiolate, collapsing when dry, with radiating mycelium or appendages at base. Peridiumcomposed of cells of textura angularis, with outer pale yellow, or brownish to brown layer, with inner hyalinelayer connected with membranous tissues. Hamathecium comprising numerous,1–2 µm wide, filiform,septate, branched, anastomosing, hyaline pseudoparaphyses.Asci 112–152(-158) ´ 12–16 µm ( = 128 × 14 µm, n = 20), 8-spored, bitunicate, fissitunicate, saccate or cylindric-clavate, sessile or with a pedicel, sometimes as long as ca. 21–24(-33) µm, apically rounded, with or without an ocular chamber. Ascospores (53-)59–73(-78) ´ 4–6 µm ( = 65 × 5 µm, n = 20), overlapping fasciculate, elongate, cylindric-subfusiform or narrowly oblong, tapering towards narrow, subacute ends, (9-)10–11(-13)-septate, not constricted at median septum, hyaline, occasionally pale brown, guttulate when immature, smooth-walled.Asexual state: Unknown.
Material examined: USA, Tennessee, Blount Co., Great Smoky Mountains National Park, 25 mi W Gatlinburg, Cades Cove, Gregory Ridge Trail, alt. 1950 ft. 35°33’45”N 83°50’45”W, on rotten wood of unindentified angisoperm, A.Y. Rossman,6 September 2005 (BPI871087), living culture = CBS 120503 = AR 4206.
Notes: Nectria paludosaP Crouan &H Crouan was placedinTubeufia as T. paludosa (P. Crouan & H. Crouan) Rossman based on its bitunicate asci (Rossman 1977). Tubeufia paludosa was also considered an earlier name forT. javanica, by Rossman (1977). Barr (1980) consideredT. paludosa dissimilar fromT. javanica, but accepted the synonymy in view of the similar coloured ascomata and cylindrical ascospores. The original descriptions of T. paludosa and T. javanica are similar in having ovoid, translucent, light-colored ascomata, filiform, cylindrical asci and filiform, hyaline and guttulate ascospores (Saccardo 1883; Saccardo and Sydow 1899). However, the illustrations of Tubeufia javanica in Penzig and Saccardo (1904) and T. paludosa in Samuels et al. (1979) and Sivanesan (1898) indicate there are differences in structure of the ascomata. Samuels et al. (1979) examined and described T. paludosa, and considered the asexual state found near the ascomata to be helicomyces-like. Tsui et al. (2006, 2007), Tsui and Berbee (2006),Schoch et al. (2009)and Promputtha and Miller (2010) investigated the molecular phylogeny of Tubeufia paludosa. Their phylogenetic analyses suggest that T. paludosa is related with the helicosporous asexual morphs. We therefore consider the collection BPI 871087 to beTubeufia paludosa (CBS 120503 as epitype). On the basis of phylogenetic placement (Clade G, Fig. 2), two cultures of Tubeufia paludosa (from CBS 120503 and AR 4206) are related with an asexual species Helicosporium indicum Rao & D. Raowith 73% BS and 0.96 PP supports. An authentic strain of Helicomyces roseus(CBS 283.51) and Helicosporium talbotii(MUCL 33010) cluster with 92% BS support and also form a subclade with Tubeufia paludosa with 76% BS and 0.99 PP support within Helicomyces sensu stricto (Clade G).
Fig. 1 Helicomyces paludosa (BPI 871087, CBS 120503;re-illustrated from Hyde et al. 2013). a Ascomata seated on sparse hyphae. b Squash mount of ascoma showing peridium. c Pseudoparaphyses. d Asci with thickened apex. e-g Ascospores. Note asci and ascospores in cotton blue reagent. Scale bars: a=100µm, b,e-g=20µm, c=5µm, d=50µm