Lepra aspergilla
Description from Cannon et al (2021) below.
Thallus rather thin to moderately thick, even, sometimes ± fissured or cracked-areolate; prothallus indistinct, marginal, often paler; upper surface pale or dark grey; soralia ± evenly scattered, to 1 mm diam., white,punctiform, flat or somewhat convex, rounded; isidia very rare, small, cylindrical. Apothecia unknown. Thallus C–, K+ dirty yellow-brown, KC+ yellow-red, Pd+ orange-rust red, UV– (fumarprotocetraric (major), succinprotocetraric (major) and ± protocetraric acids).
Characterised by the small, pale, punctiform soralia and succinprotocetraric acid in concentration above or equal to fumarprotocetraric acid. The soralia in L. amara are KC+ violet and taste bitter; those in Varicellaria lactea are C+ red; L. excludens is K+ red and mild-tasting; specimens on lignum in relict Scottish pine woodlands previously referred here are L. borealis. See also L. leucosora.
On siliceous outcrops, scree and walls, mainly upland.
![Key to map date classes](/sites/default/files/default_images/species-maps-key_2.png)
Fairly frequent and widespread except in S.E. and C. England.
Cannon, P., Kukwa, M., Coppins, B., Fletcher, A., Sanderson, N. & Simkin, J. (2021). Pertusariales: Ochrolechiaceae, including the genera Lepra, Ochrolechia and Varicellaria. Revisions of British and Irish Lichens 5: 1-17. Link