Crassoascoma Jian K. Liu, gen. nov.
MycoBank number: MB 841098; Index Fungorum number: IF 841098; Facesoffungi number: FoF;
Etymology: Referred to superficial thick-walled ascoma.
Saprobic on the living and decayed branches of Potentilla fruticosa L. (Rosaceae). Sexual morph: Ascomata superficial, solitary to gregarious, subglobose to globose, dark brown to black, ostiolate, with setae around the papilla. Peridium with multi-layers, comprising hyaline to brown cells of textura angularis. Hamathecium trabeculate pseudoparaphyses, filamentous and anastomosing. Asci 8-spored, clavate to subcylindrical, short pedicel. Ascospores overlapping biseriate, usually uniseriate in the lower half, fusiform, straight or slightly curved, hyaline to pale brown, 1-septate constricted at the septum and midpoint of each cell, surrounded by an entire mucilaginous sheath. Asexual morph: Undetermined.
Type species: Crassoascoma potentillae Z.P. Liu, S.N. Zhang and Jian K. Liu
Notes: – The phylogenetic analyses showed that four isolates of Crassoascoma formed a monophyletic clade in Lentitheciaceae and is sister to Darksidea with high statistical sup- port (98/95/1.00). Darksidea accommodates endophytic fungi which are characterized by 4–6-spored, clavate to ellipsoid asci and ellipsoid, aseptate ascospores [9]. Crassoascoma however, is distinct from Darksidea in having superficial, papillate, thick-walled ascomata with setae around the ostiole, clavate to subcylindrical asci, and fusiform, 1- septate ascospores surrounded by a mucilaginous sheath. Multi-gene phylogeny results also indicated a close relationship of Crassoascoma to Lentithecium and Halobyssothecium. The sexual morphs of these three genera are somewhat similar, and all have eight-spored, clavate to subcylindrical asci, fusiform ascospores with septa that constricted at median septum. However, Lentithecium contains saprobic species from aquatic habitats, usually have semi-immersed, thin-walled ascomata, and fusiform, hyaline, or yellowish-brown ascospores, with or without a sheath [8,53,54]. The superficial, black, thick-walled ascomata of Crassoascoma resemble species in Halobyssothecium [10,55], but they can be distinguished by the ascospores (hyaline to pale brown vs. versicolored; with sheath vs. lacking sheaths or appendages) and habitat (terrestrial semiarid region vs. marine).
Species