Xanthoparmelia loxodes (images of British lichens)

Thallus foliose, forming extensive patches, light- to grey- or red-brown, slightly lustrous to distinctly glossy, lobes usually narrow, often serpentine, convex in cross-section or flattened at the tips, commonly with small, transverse ridges, usually with dense, cauliflower-like clusters of coarse, spherical isidia, lower surface black; apothecia infrequent, with dark-brown discs and pale, variably isidiate margins. Widespread, predominantly lowland and coastal on sunny rocks, in some inland areas characteristic of basalt outcrops.

Refs: Smith et al. (2009), 965; Purvis et al. (1992), 436 (as Parmelia); Dobson (2005), 278 (photo, as Neofuscelia); Dobson (2011), 468 (photo); van Herk & Aptroot (2004), 258-9 (photo, as Neofuscelia); Nordic Lichen Flora (2011) 4: 133, 173 (photo, printed too dark); Lichen Atlas of the British Isles 1: 1003 (1995) (as Parmelia).

The species of this group are difficult, variable and not always separable morphologically. X. verruculifera also has isidia, often more generally dispersed on the thallus but sometimes in dense clusters and then closely similar to X. loxodes, but the initially globose isidia tend to become taller ("broccoli" more than "cauliflower") and sometimes coralloid-branched, and the thallus is usually red- to darker brown. If X. loxodes lacks isidia then it will be scarcely distinguishable from X. pulla or X. delisei, or rarer species in the genus.

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Images of British Lichens