Tegmenticium Spirin & Viner gen. nov.

Etymology.

From ‘tegmen’ (short version of ‘tegimen’) (Lat., noun), meaning a cover or a clothing, and Corticium, in reference to the crust-like basidiomata.

Description.

Basidiomata annual, effused, waxy-gelatinous, opaque, grayish-white. Hymenial surface smooth, covered by a grayish-white, easily removable pruina. Hyphal structure monomitic; hyphae clamped, hyaline or yellowish, agglutinated, basidia-bearing hyphae poorly differentiated. Crystals normally absent. Cystidia present, thin-walled, hyaline, usually clearly tapering. Hyphidia present, with a well-differentiated stem and richly branched, non-encrusted apical outgrowths, forming a continuous layer. Basidia four-celled, ellipsoid-ovoid to subglobose, sessile, thin-walled, embedded, occasionally with a reduced stalk-like base. Basidiospores thin-walled, broadly to narrowly cylindrical, curved. On dead wood of angiosperms.

Generic type.

Sebacina peritricha Bourdot & Galzin.

This genus is introduced here for a single species, Exidiopsis (Sebacina) peritricha, which is currently synonymized with E. effusa. Our data (Figs 1, 2) show that these species should be treated separately and that they are not closely related. Tegmenticium peritrichum is different from other European species formerly treated under Exidiopsis due to its well-developed cystidia, as well as its rather small basidia and basidiospores. Its mature basidiomata are clearly gelatinized and covered by a whitish-grayish, easily removable deposit. Thus, they can be mistaken for E. effusa. The latter species, however, lacks cystidia and has larger basidia and, in most specimens, longer basidiospores. Moreover, it possesses spine-like outgrowths on its hymenial surface, although they can be detected only in fresh or rehydrated specimens. Differences of T. peritrichum from the outwardly similar Exidia repleta and E. saturata are discussed above, under E. repleta. Proterochaete abstrusa occasionally bears cystidia which are similar to those of T. peritrichum. However, P. abstrusa can be easily recognized due to its slenderer basidiomata, larger basidiospores and basidia, as well as thicker sterigmata. See further notes under Ulocolla corticioides.