Caloplaca ochracea (images of British lichens)

Thallus a thin, creamy yellow crust, surface matt and lacking an organised cortex, black prothallus visible at margin; apothecia orange to orange brown. Very locally frequent on hard limestones in Wales and western England.

Refs: Smith et al. (2009), 268; Purvis et al. (1992), 156; Dobson (2005), 106 (photo); Dobson (2011), 115 (photo); Whelan (2011), 62 (photo); Lichen Atlas of the British Isles 6: 272 (2001).

Other species, notably C. dalmatica (page pending), that have had their cortex removed by grazing snails, can be confused with C. ochracea.

lastdragon.org

Images of British Lichens