Pertusaria lactea (images of British lichens)

Thallus white to cream or pale grey, smooth to cracked-areolate or somewhat warted, reacting red with sodium hypochlorite, KOH negative, delimited soralia scattered over the surface; apothecia rare. Locally common in the north and west on exposed, base-poor or somewhat calcareous rocks.

Refs: Smith et al. (2009), 683; Purvis et al. (1992), 455; Dobson (2005), 326-7 (photo); Dobson (2011), 327 (photo); Wirth (1995), 2: 696, 707 (photo).

lastdragon.org

Images of British Lichens