Polycephalomycetaceae Y.P. Xiao, Y.B Wang, T.C. Wen, H. Yu & K.D. Hyde, fam. nov.

MycoBank number: MB 559469; Index Fungorum number: IF 559469; Facesoffungi number: FoF 10730;

Etymology: Morphology of the type genus Polycephalomyces.

Parasites on and pathogens of Ophiocordyceps sp., Elaphomyces sp. and insects. Sexual morph: Ascomata stromatic, cylindrical, pallid to yellowish, stipitate. Stipe cylindrical, simple or branched, rhizomorphs present or absent, forming inflated fertile parts. Fertile part distinct from stipe, globose to ellipsoid, ascoma congregated, capitate, with protruding ostiolar papillae. Perithecia immersed or superficial, ovoid to flask-shaped. Peridium thick, three layers. Asci unitunicate, narrowly cylindrical, hyaline, with an apical cap. Ascospores filiform, hyaline, multiseptate, often separating into secondary spores. Secondary spores cylindrical to globose, hyaline, smooth-walled. Asexual morph: Hyphomycetous. Mycelium congregated as flat colony on the surface of host or forming synnemata from host. Synnemata stipitate, single to numerous, branched or unbranched, white to yellow, with or without an enlarged fertile part on the topical or lateral. Fertile parts enlarged, normally globose, yellowish to yellow, conidia massed on the surface. Conidiophores 1-6 phialides congregated in one, branched or unbranched, divergent. Conidiogenous cells phialidic, hyaline. Phialides one or two types, congregated or solitary, intercalary and terminal. Conidia one or two types, cylindrical or fusoid or globose, hyaline, smooth, 1-celled, masses of conidia observed or not.

Type genus: Polycephalomyces Kobayasi, Sci. Rep. Tokyo Bunrika Daig., Sect. B 5: 245 (1941)

Notes:Polycephalomyces, Perennicordyceps, and Pleurocordyceps, formed a clade sister to Ophiocordycipitaceae in the Hypocreales tree (Fig. 1). Clavicipitaceae branches off the Ophiocordycipitaceae+Polycephalomycetaceae clade, followed by Calcarisporiaceae and Cordycipitaceae+Hypocreaceae (Fig. 1 and Fig. 2). Polycephalomycetaceae is distinctly separate from Ophiocordycipitaceae; the latter includes Drechmeria, Harposporium, Hirsutella, Ophiocordyceps, Polycephalomyces, Purpureocillium, and Tolypocladium.

The hosts of Polycephalomycetaceae include Ophiocordyceps sp., Elaphomyces sp., and insects (Table 8, Table 9, Table 10, Table 11, and Table 12). Morphologically, Polycephalomycetaceae is similar to Ophiocordycipitaceae and Clavicipitaceae, but differs from both in that its members parasitize Ophiocordyceps sp., and Elaphomyces sp., and produce congregated or solitary conidiophores, one- or two-type phialides, and conidia. Therefore, the new Polycephalomycetaceae family is introduced to accommodate these three genera.