Fuscidea praeruptorum
Thallus pale to dark greenish brown, areolate, unevenly verrucose. Areoles to 400 µm diam., contiguous to discrete, often thin, uneven and delimited by a black prothallus, rounded, tuberculate. Soralia 200-500 µm diam., at first pale greenish, ochre- or cream-coloured, punctiform and rounded, soon becoming brownish and ± confluent.
Anamorph: no information available.
Teleomorph: ascomata apothecia, to 0.8 mm diam., very rare, sessile, black, the disc slightly convex and a narrow true exciple. Ascospores 9.5-12 × 3-4 μm, bean-shaped.
Chemistry: soralia Pd+ yellow, KC+ red, C+ red, UV+ faintly yellowish (alectorialic acid).
Assessed by Woods & Coppins as of Least Concern.
Throughout northern and western Britain, but rare in Ireland. BLS map here.
On ± vertical, shaded, siliceous rocks, often under overhangs, in uplands; easily overlooked.