Pertusaria multipuncta (images of British lichens)

Thallus a thin to thick, more or less smooth or somewhat warted, grey crust, surface with larger, isolated, flat-topped warts, these crowned with white soredia but later maturing to contain typically two to three sunken apothecia; asci 1-spored, the spore very large. Predominently in southern and western England, Wales, western Scotland, on trunks, branches and twigs, rarely on rocks.

Refs: Smith et al. (2009), 685; Purvis et al. (1992), 457; Dobson (2005), 328 (photo); Dobson (2011), 329 (photo); Whelan (2011), 128 (photo); Arup et al. (1997), 229 (photo); Thor & Arvidsson (1999), 301 (photo).

lastdragon.org

Images of British Lichens