Description: The thickly-warted thallus of this species forms bold creamy crusts – like coloured chunks of ‘Anaglypta’ wallpaper – over rock surfaces, tree bark and soil. The large, saucer-shaped, orange-pink discs (5–8mm diam.) can be abundant or altogether absent. This is a non-sorediate species unlike its lookalike O. androgyna but occasionally the two get mixed up. The thallus of O. tartarea should react better in K and turn pale yellow; O. androgyna is K-. The species was once widely harvested to make dye. In Ireland, the species is widely scattered, but is nowhere common.

Key Identification Features:

• Heavyweight crustose lichen; cream coloured warty thallus with orange-pink discs when mature
• Non-sorediate; K+ pale yellow, C+ red.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Ochrolechia tartarea at iNaturalist World Species Observations database.