Parmelia discordans (images of British lichens)

Thallus foliose, uniformly rather dark brown, green-tinted when wet, closely similar to the more common P. omphalodes, differing in the more appressed growth, somewhat narrower lobes (narrowest subdivisions about 1mm wide, not the whole lobes as books might suggest) and less conspicuous pseudocyphellae, but best confirmed by chemical tests. Local in the north and west, on exposed, upland, base-poor rocks.

Refs: Smith et al. (2009), 652; Purvis et al. (1992), 425; Dobson (2005), 302; Dobson (2011), 305; Nordic Lichen Flora (2011) 4: 86, 162 (photo, as P. omphalodes subsp. discordans, printed too dark); .

lastdragon.org

Images of British Lichens