A crustose species that consists of very small, chocolate-brown, coralloid granules or isidia. Apothecia may be scattered across the thallus.
Thallus: C+ red, K-
In Scotland, Placynthiella icmalea is widespread on tree stumps and fenceposts, tree stumps, and it may also form crusts on soil in acid heathland. BLS distribution map
On soil in acid heathland Placynthiella icmalea is often found alongside Trapeliopsis granulosa.
scottishlichens.co.uk 