Acanthostigma De Not., Hedwigia 4: 28 (1865)
Index Fungorum number: IF 16; Faceoffungi number: FoF 06813, 41 morphological species (Species Fungorum 2021), 1 species with molecular data.
Saprobic on dead plant debris. Ascomata superficial, scattered, globose to subglobose, reddish-brown to dark brown, collapsing when dry, sparsely setose on the upper part, setae dark brown to opaque. Peridium consisting of several-layers of polyhedral cells. Hamathecium numerous, cellular, branching and anastomosing pseudoparaphyses developing from the basal hymenium. Asci 8-spored, bitunicate, fissitunicate, clavate, broadly rounded and thickened at the apex, short pedicellate. Ascospores fusiform, narrowly rounded at both ends, one of middle cells often broader than the others, trans-septate, straight or slightly curved, not-constricted or slightly constricted at the septa, hyaline.
Type species: Acanthostigma perpusillum De Not
Notes: Acanthostigma was introduced by De Notaris (1865) with A. helminthosporus as type species. Acanthostigma was revised by Réblová and Barr (2000) and the type was re-described by Berlese (1894).