Fulgensia fulgens (images of British lichens)

Thallus squamulose or forming a crust with lobed edges (placodioid), egg yellow, strongly pruinose, with surface at the centre forming flake-like shizidia that break away to expose the white medulla; apothecia orange, with narrow, thalline margins. A rare and declining species of calcareous soils, on dunes and where sand has blown over limestone, on coasts of south-west England and S. Wales; formerly on chalk at a few sites further east and in Breckland but apparently now extinct in these areas.

Refs: Smith et al. (2009), 406; Purvis et al. (1992), 251; Dobson (2005), 176 (photo); Dobson (2011), 182 (photo); Jahns (1983), 248-9 (photo); Wirth et al. (2004), 397 (photo); Wirth et al. (2004), 174 (photo); Moberg & Holmåson (1984), 189 (photo); Thomson (1997), 229-30 (photo).

F. fulgens was part of a remarkable community of rare species that has largely vanished from the East Anglian Breckland, no doubt partly due to major habitat destruction of this unique area, but seemingly also as a result of atmospheric nitrate/ammonia deposition from traffic fumes and agricultural drift, with consequently enhanced competition from pleurocarpous mosses, grasses and other vegetation. See, e.g., Rare lichens in Breckland are dying.

lastdragon.org

Images of British Lichens