Biatoridium J.Lahm ex Körb.
Type : Biatoridium monasteriense J.Lahm ex Körb.
Description : Thallus crustose, granular to endophloeodal, effuse, without a prothallus. Photobiont chlorococcoid. Ascomata apothecia, biatorine, pale yellowish to brownish, plane to convex with exciple of textura globulosa. Hymenium 50–80 μm tall, colourless, euamyloid. Asci clavate, with layered amyloid ascal gel and amyloid internal cap, polysporous. Hamathecium of paraphyses, only slightly branched, apices swollen or not. Ascospores globose, simple, colourless. Conidiomata not known.
Biatoridium is a genus of two species, described originally for crustose lichens having polysporous asci, and discocarp apothecia with a proper margin and often included in the genus Biatorella. Hafellner (1994d) defined Biatorella in a more restricted sense and resurrected Biatoridium for two corticolous taxa B. monasteriense and B. delitescens, the latter of which was recently recorded from New Zealand (Malcolm & Vezda 1997a), the first time this species has been recorded outside Europe. Biatoridium is readily distinguished from other accepted genera of biatorelloid lichenised fungi (e.g. Biatorella, Myrionora, Sarcosagium, Strangospora) by apothecial characters (exciple texture, ascus type); however, it is not readily assigned to an existing family at present and is included in Lecanorales, genera incertae sedis (Hafellner 1994d; Erikssson et al. 2004; Pennycook & Galloway 2004).
