Physcia leptalea (Ach.) DC. forme corticole.

    Thallus foliose, 5-10 cm across, lobes strap-shaped, 1-2 mm wide, more or less ascending, marginal cilia, mainly towards apices, cilia white, tips seldom darker, upper surface pale grey-greenish, very pale grey, covered with white pseudocyphella giving a flecked aspect when moist and whitish when dry, soralia absent, lower surface withish with sparse brown-tipped rhizines. Usually rather fertile, apothecia 2-3 mm, disc brown-purple, purple-blackish, purplish, thinly pruinose, tinged grey-bluish, thalline exciple thick, concolourous to the thallus. Ascospores brown, ellipsoid, thick-walled, 1-septate, 15-22 x 6-9 µm according to the literature; 14-19 x 7-9 (10) µm according to our measurements.. Cortex : C-, K+ yellow, Pd- ; medulla : K-. Coastal trends, common on small trees and bushes near the seashore, often together with Teloschistes chrysophthalmus in our prospection area, sometimes forming larges colonies on tree trunks, seldom on rocks, see: Physcia leptalea forme saxicole. The absence of soredia may allow a distinction from other ciliate Physcia, notably Physcia adscendens and Physcia tenella which are sorediate  (but this might be difficult for young specimen) and especially of Physcia aipolia with brown apothecia and larger and more greenish lobes (but there are embarrassing intermediaries) and with Anaptychia ciliaris which is darker brown without pseudocyphella and K-.