Umbilicaria cylindrica var. cylindrica (images of British lichens)

Thallus attached at central point, divided into multiple lobes, grey to brownish-grey above, lacking isidia, lower surface pale brown, with variable complement of often flattened, pale rhizinomorphs (non-attaching rhizines), lobe margins with variable development of fringing, grey-brown cilia, seemingly better developed on lobes without apothecia, thalloconidia absent; apothecia black, somewhat raised, disc with multiply infolded margins (gyrose). Distribution of the species: locally common on exposed rocks and boulders in the north and west, generally upland; the variety evidently widespread within this range.

Refs: Krzewicka (2004), 24 (the species), 26 (the variety); Smith et al. (2009), 915 (for species); Purvis et al. (1992), 618 (for species); Dobson (2005), 436 (description only, for species, photo is var. fimbriata); Dobson (2011), 443 (description only, for species, photo is var. fimbriata); Whelan (2011), 147 (photo, as species); Hansen & Anderson (1995), 67 (photo, as species); Puntillo (1996), plate 41 (photo, as species).

A very variable species, with several named varieties — see Kershaw (1961) and Krzewicka (2004). Var. fimbriata is a distinctive morph, treated separately here, but it probably intergrades with this and other variants. Var. denticulata is also given separate treatment here.

lastdragon.org

Images of British Lichens