Verrucaria macrostoma f. macrostoma

A widespread species on limestone, mortar and calcareous sandstone, in both natural habitats and lightly nutrient enriched anthropogenic sites. The areolate thallus is well-developed, mid-brown and can display frequent blastidia on the edges of the secondary areoles. The black perithecia form low to moderate conical-hemispherical projections and do not develop pits.

Listed by Alan Orange in Flora of Glamorgan (Wade et al, 1994).