A foliose species with often mint-grey thallus. The lobes can be large and rising, with crisped margins which are often fringed with branched isidia or coarse soralia. The under surface of the lobes is often may pale or become brown or black.
Upper cortex: K+ yellow. Medulla: C-, K-, UV-
Platismatia glauca is common throughout Scotland, in upland areas in particular. It can be found on a wide range of acid-barked trees, especially on top of horizontal branches, and sometimes on siliceous rocks, including gravestones. BLS distribution map
Platismatia glauca can be distinguished from Tuckermannopsis chlorophylla by the pale mint grey to grey, rather than brown when dry and olive-green when wet, upper surface of the lobes. Platismatia glauca is distinguished from Platismatia norvegica by the presence of domed, rather than flat-topped, ridges on the lobe surface and the presence of isidia on the lobe margins.
scottishlichens.co.uk 