Description: This upland, crustose lichen of exposed, siliceous rocks is a common enough species. However, for beginners there are few distinctive features which can help ‘nail it’ in the field. The grey to brown, slightly shiny, much divided and broken (areolate) thallus has one important feature: the fact that it is often a pastiche of warted and flat areoles. It is rare to find it as one or another — but now to the discs: these are numerous but unevenly distributed, a mixture of convex and flat forms (to 1mm diam.), usually black (on north-facing rocks they often lack pigmentation and may be pale brown or chestnut and rather shiny like fruit gums). Spot tests negative. Northern and south-west Ireland.

Key Identification Features:

• Spot tests negative; grey-brown, flat and warted thallus, minutely divided
• Discs black or shiny brown to 1mm diam. not much larger than the areoles; simple spores.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Miriquidica leucophaea at iNaturalist World Species Observations database.