Click on map to open large map in new window
(Map updated: 11 August 2009)

This is a non-sorediate, mosaic-forming, crustose lichen of hard, siliceous upland rocks. The brown-grey thallus is minutely crazed (cracked). The resultant pieces (areoles) are irregular, angled and spotted with discs, largely immersed, so appearing only as small pips. This gives the surface a distinctive jizz. Spot tests: C+ pink-red, sometimes fainter on thin or specimens exposed to extreme conditions. Western Ireland with outliers in the south and east.

Key characteristics

• Mosaic-forming, acid-rock lichen with a brown-grey thallus, crazed into areoles each with immersed discs just visible as spots
• Spot test: C+ pink-red (but can be patchy); try several candidates.

Original text submitted by Vince J. Giavarini