Lecidella asema (Nyl.) Knoph & Hertel var. asema s.l.

    Thallus rather thick, coarsely granulose, more or less markedly cracked, cracks delimiting large granulose heaps, pale ochre, pale greyish tinged with pale fawn or grey-greenish, green-yellowish, most often delimited by a black prothallus. Apothecia numerous, 0.5-1 mm diam., immersed at first, then more or less sessile, little protruding, flat, disc very black more or less bluish-whitish powdery, then convex, brown-blackish, exciple disctinct, paler at first soon excluded. Ascospores simple, ellipsoid, 10-13 x 6-9 µm. Photobiont: chlorococcoid. Thallus: C+ orange, K +/- yellowish, KC+ orange, Pd-. Pycnidia usually numerous and immersed in the thallus. Rather common, on well exposed and well-lit siliceous rocks (shales) in the xeric supralittoral zone.

N.B. Some authors agree on the existence of two varieties (and some intermediates that may grow together in the same site and even on the same rock depending on exposition), var. asema with fawn, pale grey-greenish or pale green-yellowish and var. eleaeochromoides, ochre-reddish or brown-reddish, more thermophile and Mediterranean (see this variety).

N.B. There are several chemoforms, see Lecidella asema s. str. limited to the xeric supralittoral zone and the spray zone.

N.B. When blastidia are present and apothecia scarce, see Lecidella meiococca. When the thallus is yellow-greenish to greenish, more or less covered with green-yellowish sorela heaps, see Lecidella scabra.