Physciaceae Physcia tribacioides Chemical results: Cortex and medulla K+ yellow Scarce on well-lit, nutrient-rich wayside trees in S England and Ireland. Very rarely recorded from rocks. BLS conservation evaluation: VU C1, D1 NS P Eng Wa S8 Thallus of adpressed, +/- overlapping grey-white lobes without pseudocyphellae. The marginal lobes widen and are notched at tips, under surfaces pale whitish-brown with sparse rhizines. Abundant convex, +/- hemispherical, laminal soralia can cover centre of thallus. The reddish-brown apothecia are rare. Similar: Physcia tribacia, cortex K+ yellow, medulla K- and Phaeophyscia orbicularis

Physcia tribacioides
Knoll car park, Studland and on gravestone, East Holme, Dorset. May and December 2015