Placynthiella icmalea (Ach.) Coppins & P. James

One of the most abundant microlichens in the Czech Republic. It forms a finely coralloid isidiate thallus of a greenish, ochraceous or even dark brown colour depending on sun-exposure and water content. It grows on practically all acidic substrates, mainly decaying wood, humus or plant detritus. It is abundant in both forests and open habitats. In forest communities, P. icmalea belongs to the most common lichen species.

Underdeveloped or atypical specimens from very shady places may resemble P. dasaea, so secondary metabolites need to be verified by TLC for identification. The two species often grow together, which makes the identification more difficult. In historical literature, it is referred to as fuliginea, although a part of the records may in fact belong to P. dasaea.

Ascomycota → Lecanoromycetes → Trapeliales → Trapeliaceae → Placynthiella