Occultibambusa D.Q. Dai & K.D. Hyde, in Dai et al., Fungal Divers. 82(1): 25 (2017).
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 (Adapted from Dai et al., 2017).
Type species: Occultibambusa bambusae D.Q. Dai & K.D. Hyde
Notes: Occultibambusa was introduced by Dai et al. (2017) with O. bambusae as type species. Occultibambusa is characterized by solitary, scattered ascostromata, broadly cylindrical to clavate asci, broad-fusiform, 1-septate ascospores surrounded by a gelatinous sheath, guttulate. The asexual morph is characterized by eustromatic globose to subglobose, black conidiomata, ampulliform to cylindrical, smooth-walled conidiogenous cells and oblong, aseptate, pale brown to hyaline conidia. Occultibambusa differs from other genera in Occultibambusaceae in producing black necks at the center of conidiomata. Occultibambusa resembles Bambusicola in having pale brown, oblong conidia but differs in having enteroblastic, phialidic conidiogenous cells while Bambusicola has annellidic conidiogenous cells. Members of Occultibambusa also resembles species of Lophiostoma, and Massarina in having fusiform ascospores and clavate asci (Zhang et al., 2009; Dai et al., 2017). Occultibambusa differs from Lophiostoma in having papillate ascomata while species of Occultibambusa have ascomata with a compressed or crest-like ostiole. Occultibambusa differs from Massarina in having cylindrical to clavate asci while those of Massarina are cylindrical or oblong (Zhang et al., 2009; Thambugala et al., 2015; Dai et al., 2007). Occultibambusa is morphologically and phylogenetically a distinct genus in Occultibambusaceae. Molecular markers available for Occultibambusa are LSU, SSU, ITS, TEF1 and RPB2.