Psilolechia lucida (images of British lichens)

Thallus a thin to granular, powdery, yellow-green to sulphur yellow crust, in places thicker and irregularly cracked; apothecia rare, very small, yellow-green to orange. Common throughout Britain, often in somewhat shaded situations, generally on base-poor rock, especially crevices in drystone walls, rarely on bark, also common but easily overlooked on urban brick and stonework.

Refs: Smith et al. (2009), 763; Purvis et al. (1992), 508; Dobson (2005), 371-2 (photo); Dobson (2011), 375 (photo); Wirth et al. (2004), 304 (photo); van Herk & Aptroot (2004), 324-5 (photo, atypical); Wirth (1995), 2: 784 (photos); Moberg & Holmåson (1984), 124 (photo, as Lecidea lucida); Holien & Tønsberg (2008), 185 (photo); Brodo et al. (2001), 596 (photo).

When on bark, very difficult to separate from Chrysothrix candelaris or barren Chaenotheca furfuracea, and could also be confused with Bacidia adastra, on rock could be confused with Lepraria ecorticata (page pending) or perhaps with densely sorediate states of Lecanora orosthea.

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Images of British Lichens