Thallus consisting of very thin, papery, irregularly folded and crumpled, glabrous lobes, each approx. 1cm in width, green-grey, blue-tinted when dry, margins entire, somewhat revolute, isidia absent; apothecia very rare. In mossy places on rocks, rarely walls, strictly coastal and confined to the west.
Refs: Smith et al. (2009), 545 (but error in dimensions); Purvis et al. (1992), 352 (but error in dimensions); Dobson (2005), 247 (photo); Dobson (2011), 253 (photo, but text error in dimensions); Nordic Lichen Flora (2007) 3: 33, 184 (photo).
There is a typographical error in Purvis et al., in which lobe dimensions were incorrectly given in mm instead of cm. This error has been copied into Smith et al., and while the description in edition 5 of Dobson (2005) was correct, the erroneous dimensions have also been copied into edition 6 (2011). Best to use the excellent account of the genus in the Nordic Lichen Flora!