Description: The pale brown thallus of this crustose lichen grows on gritty sandstone outcrops and boulders in upland areas. It forms small, uneven crusts easily hidden between the thalli of other species. The pale green to ochre soralia against the darker thallus is usually the most reliable field character for identification as this feature can be spot tested to give a C+ red reaction. It is also Pd+ yellow. Unlike other acid-rock-inhabiting Fuscidea species, it is not a 1 mosaic-forming species. In Ireland, it is generally rare and very thinly scattered.

Key Identification Features:

• Thallus verrucose-warty, pale brown with scattered, green to ochre-coloured soralia, C+ red, Pd+ yellow
• Siliceous rocks: gritty or conglomerate boulders, exposed sandstones and low-level outcrops.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Fuscidea praeruptorum at iNaturalist World Species Observations database.