Verrucaria romeana

Before 2013, Verrucaria romeana was regarded as a form of V. viridula. The species is typically found on artificial, basic substrates such as stone, brick or concrete, usually where conditions are sheltered and damp. Green when wet, becoming paler brown when dry, the thallus comprises overlapping, incised sub-squamulose areoles on a black involucrellum, in which the perithecia are embedded. Chemical results all negative. Recorded recently on medium lumps of concrete sitting in seasonally damp grassland at Fairwood Airport.

Not listed by Alan Orange in Flora of Glamorgan (Wade et al, 1994).