Crocodia aurata  

Thallus 2–6 (–10) cm diam., forming rosettes or irregularly spreading; lobes 3–12 mm broad, rounded or indented at the apices, often discrete at margins and overlapping centrally; upper surface bright green when wet, pale grey when dry, smooth, undulate, often scabrid-areolate in parts, ± pubescent at the margins, bearing conspicuous coarsely granular bright yellow ± linear lip-like marginal soralia which occasionally also spread on to the upper surface; medulla yellow; lower surface pale pink-brown, darker towards the centre, thickly tomentose to the margins, ± wrinkled-uneven with numerous yellow pseudocyphellae, 0.1–0.6 mm diam.; photobiont green. Medulla and soralia C–, K–, KC–, Pd–, UV+ dull to bright orange or salmon-pink (pulvinic acid, pulvinic dilactone and calycin).

Information abstracted from Revisions of British and Irish Lichens vol. 20 (2021).