Wingspan 25-35 mm.
A primarily woodland species, which is distributed locally in the south and west of England and Wales, and parts of Ireland. Occasional records from elsewhere are considered to be probable migrants.
The single generation flies in June and July, when it can sometimes be found flying in the daytime. It is also nocturnal, coming to light.
Feeding on lichens and algae growing on tree-trunks, the larvae live in autumn, and the species overwinters as a pupa.