Peltigera canina (images of British lichens)

Upper surface of fresh thallus grey-brown, with convex wrinkles ('bullate') (compare P. rufescens), ash-grey and lacking wrinkles when dry, densely but minutely felted-tomentose, lacking isidia, margins of main lobes generally down-turned towards the tips but side-margins often erect, crisped-undulate (beware key in Smith et al. (2009)!), lower surface white-tomentose, with irregular, fluffy, confluently-based rhizines. Widespread but local in turf on dunes and on gravelly and sandy soils inland.

Refs: Vitikainen (1994) 29-32 (photo); Smith et al. (2009), 667; Purvis et al. (1992), 443; Dobson (2005), 315 (photo); Dobson (2011), 316 (photo); van Herk & Aptroot (2004), 282-283 (photo); Nordic Lichen Flora (2007) 3: 116, 192 (photo); Moberg & Holmåson (1984), 172 (photo); Holien & Tønsberg (2008), 122 (photo); Brodo et al. (2001), 506-7 (photo); Hinds & Hinds (2007), 358-9 (photo); McCune & Geiser (2009), 239 & 244 (photos).

Over-reported and confused with the larger and much commoner P. membranacea. In dry state, closely resembles P. rufescens, with which it commonly grows; attention to characters of the lower surface is required.

lastdragon.org

Images of British Lichens