Xanthoria elegans (images of British lichens)

Foliose, with yellow to deep orange, very narrow (< 1mm), adpressed, somewhat serpentine lobes, lacking isidia or soredia; apothecia usually abundant, concolorous with the thallus or more deeply coloured. On nutrient-enriched rocks, walls, concrete; widespread and locally common, though tending to be more frequent in upland areas.

Refs: Smith et al. (2009), 969; Purvis et al. (1992), 646; Dobson (2005), 463 (photo); Dobson (2011), 472 (photo); Fox et al. (2003), plate 8 (photo); Jahns (1983), 248-249 (photo); van Herk & Aptroot (2004), 396-7 (photo); Wirth (1995), 2: 973, 975 (photo); Wirth et al. (2004), 153 (photo); Moberg & Holmåson (1984), 192 (photo); Holien & Tønsberg (2008), 104 (photo); Puntillo (1996), plate 42 (photo); Hansen & Anderson (1995), 72 (photo); Pope (2005), 29 (photo); Hinds & Hinds (2007), 523 (photo); Brodo et al. (2001), 744 (photo); Walewski (2007), 82-3 (photos); McCune & Geiser (2009), 396 (photo); Øvstedal & Lewis Smith (2001), 362, plates 73 & 103 (photos).

Small thalli can very easily be confused with placodioid Caloplaca species, but X. elegans is truly foliose, with a lower cortex and can be peeled from the substrate. Very similar but isidiate and usually lacking apothecia is the circumpolar arctic-alpine species, X. sorediata, not yet found in the British Isles.

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Images of British Lichens