Description: This species is similar to C. foliacea (described elsewhere), but has a distinctive grey-violet hue to the lower surface of the squamules (0.4–1cm tall) and a K+ yellow thallus. The species grows on rather basic soils. It never grows with C. cervicornis, a lichen of acid soils, which also has a grey-violet underside, but different chemistry. In Ireland, it has been recorded from a few localities, for example, Counties Donegal and Londonderry.

Key Identification Features:

• Thallus not unlike C. foliacea but with squamules grey-violet below. K+y
• On neutral to basic soils often near the coast.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Cladonia firma at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Cladonia firma at iNaturalist World Species Observations database.