Occultibambusa D.Q. Dai & K.D. Hyde, gen. nov. , Index Fungorum number: IF552013

Etymology: Occulti means hidden in Latin, and refers to members of this genus hidden on bamboo substrates.

Saprobic on dead bamboo culms, forming dark, round, black spots on host surface, with ascostromata on raised areas, with an ostiolate oppening. Sexual morph: Ascostromata solitary, scattered, immersed under host tissue, subglobose, conical in section, uni-loculate, black at ostiolar region, coriaceous, with a central, papillate, rounded ostiole, internally lined with periphyses. Peridium comprising host and fungal tissues, composed of brown and thick-walled to hyaline and thin-walled cells of textura angularis intermingled with host cells. Hamathecium composed of long, septate, cellular pseudoparaphyses above the asci. Asci 8-spored, bitunicate, broadly cylindrical to clavate, with a short furcate pedicel, and a shallow ocular chamber. Ascospores 2–3-seriate, broad-fusiform, 1-septate, usually with larger upper cell, narrowly acute at both ends, dark brown, straight to curved, surrounded by a gelatinous sheath, guttulate. Asexual morph: Coelomycetous, produced on bamboo pieces on WA. Conidiomata eustromatic, immersed to partly-immersed, solitary to gregarious, globose to subglobose, black, with a black papillae or short neck. Wall of conidiomata comprising several layers, composed of dark to hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells enteroblastic, phialidic, determinate, ampulliform to cylindrical, smooth-walled. Conidia oblong, aseptate, pale brown to hyaline, rounded at the apex, smooth-walled, guttulate.

Type species: Occultibambusa bambusae D.Q. Dai & K.D. Hyde

Notes: The genus Occultibambusa is characterized by immersed, dark coloured, ascostromata with periphysate ostioles, broad cylindrical to clavate asci, and dark brown, fusiform, 1-septate ascospores. The asexual morphs of Occultibambusa produce black necks at the center of the conidiomata. This character is not observed in other genera of the family Occultibambusaceae. Characters such as pale brown and oblong conidia are similar with Bambusicola species (Dai et al. 2012), however, annellidic conidiogenous cells are not observed in Occultibambusa.