Agyriaceae Trapelia placodioides Growth type crustose / placodioid Chemical results: K-, C+ red, KC+ red, P-, UV+ white Can be common on siliceous rocks, walls and mine-spoil heaps, most frequent in northern and upland areas Thallus creamy to pinkish-white, forming small patches or a continuous areolate crust, the outer margins +/- placodioid. Powdery yellowish-white or pale green soralia present but apothecia are very rare. Similar: T. coarctata and T. glebulosa. C+ red, soralia absent.

Trapelia placodioides
Corfe Mullen and Wareham, Dorset. February 2014, December 2016