Trapeliopsis granulosa (Hoffm.) Lumbsch

     Thallus strongly granular formed of agglomerated warty or granular areoles, pale greyish, cream, sometimes with pinkish zones, in dry weather, more pale greenish grey, yellowish green,... in humid weather, frequently with pale greenish-yellow soredia. Apothecia frequent, lecideine, 0.3-1.5 mm in diameter, disc flat then convex and sometimes tuberculate in appearance, pinkish-brown, reddish-brown, then blackish-grey and blackish, margin paler, thin, quickly excluded. Spores elliptical, hyaline, simple with thick wall, 8-15 x 4-7 µm. Photobiont: chlorococcoid. C+ red, K-, KC+ red, P-, UV+ white-blue. A pioneer species with mountain or alpine tendencies, unspectacular and therefore often overlooked, growing in the black humus rich in woody debris in acidic soils, or at the base of stones and rocks in heather moors, rarely on rotten wood.

_ See non-fertile Trapeliopsis pseudogranulosa with a more finely granular thallus with orange spots and growing more on damp plant debris (Recent studies seem to show that this taxon is very similar, if not identical, to Trapeliopsis granulosa).

_ On slightly rotting wood, consider Trapeliopsis flexuosa with its gray-green-blue "aeruginous" thallus.

_ Along the seashore, consider Trapeliopsis wallrothii, whose thallus is always whitish and the apothecia with pink or reddish tones.

N.B. A highly variable polyphyletic "species" for which recent studies have shown that there are several taxa under this name, ss. str. would be boreal or alpine.