Description: The pale yellow to orange thallus of this species is so finely divided it appears to be disintegrating before your very eyes. In fact the convex, granular, radiating lobes are barely 1mm diam., and these are further covered in granular isidia, often forming little heaps scattered across the thallus. Pale orange-coloured discs are common. In sheltered crevices in cliffs and also bird perching rocks above the shoreline on siliceous rocks. It is grossly under-recorded in Ireland.

Key Identification Features:

• The granular lobes with spherical isidia of many sizes is typical; C. littorea is brighter, entirely crustose with finger-like isidia
• It inhabits the sheltered faces of vertical sea cliffs (at the top of the ‘orange zone’) and in places can be abundant.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Haloplaca britannica at iNaturalist World Species Observations database.