Description: The uneven, thick, grey thallus of this species can be warted and nodular (the texture of porridge). Black, convex discs (0.7-1.7mm diam.) that tear open to reveal a blood-red-like pigment are frequent. This is stored in the tissue which accumulates at the base of the discs. So distinctive is the reddening (sometimes described as carmine), there is no other like it. M. sanguinarius overgrows mosses, bark (especially acid-barked birch and pine), wood and soil and can spread over several centimetres. Scattered, northern and eastern Ireland.

Key Identification Features:

• Grey, porridge-textured thallus; abundant, black, convex discs breaking to reveal a carmine-red pigment looking like flecks of blood
• Birch-bark and mosses overgrowing siliceous rocks.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Mycoblastus sanguinarius f. sanguinarius at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Mycoblastus sanguinarius f. sanguinarius at iNaturalist World Species Observations database.