Lecanora varia (images of British lichens)

Thallus a thin, pale to yellowish, dispersed-granular to continuous nodulose crust, soredia absent; apothecia usually abundant and often crowded, discs yellow- to red-brown or greenish, thalline margins white, conspicuous, smooth to irregularly distorted or warted. Widespread and often common on worked wood, less often on bark.

Refs: Smith et al. (2009), 501; Purvis et al. (1992), 318; Dobson (2005), 233 (photo); Dobson (2011), 235-6 (photo); Moberg & Holmåson (1984), 116 (photo); Wirth (1995), 1: 460; Thomson (1997), 310-11 (photo).

L. confusa (page pending) can resemble this species and sometimes occurs on worked timber. Unlike L. varia its thallus gives a positive (orange) reaction with sodium hypochlorite, and it has longer, narrower spores, given as approx. 10-14×4-5µm (Edwards et al. in Smith et al., 2009), whereas L. varia has egg-shaped spores, approx. 10-12×6-7µm (my measurements). I have seen the two species growing side by side on old railway sleepers.

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Images of British Lichens