A distinctive species with conspicuous convex pustules across its surface that become pruinose toward the centre. The rounded, foliose thalli are up to 8cm in diameter, centrally attached, pale grey/brown when dry, becoming brownish to yellowish green when wet. The margins are often ragged and darkened by black isidia. This lichen has been used for dyeing and also as a survival food.

Nutrient-enriched rocks in Western/upland regions.

All year.

Common in the right habitat.

VC55 does not fall within the normal range for this species but an outlier population exists in the Charnwood Forest area.