Verrucaria consociata

Verrucaria consociata Serv. (1951): on shaded stone in stream in woodland, Afon Tuen, south of Penrhiw, Ystumtuen, VC 46, Cardiganshire, GR 22/357.400, 21 May 2010, A. Orange 18878 (NMW). Thallus thin, minutely granular, composed of goniocyst-like units; perithecia small, c. 200 µm diameter, prominent (or partly covered by thallus), involucrellum more or less absent, ascospores medium-sized, c. 20-27 µm long. Probably widespread.