Nephroma laevigatum Ach.

    Thallus foliose, up to 15-20 cm across, lobes relatively thick, 0.5-1 cm wide, upper surface smooth and glossy with metallic glints, brown-greyish, brown-reddish, bronze, grey-blue when dry (colour highly variable according to hydration), lower surface pale brownish, darker and blackish towards the center, almost smooth ; medulla pale yellow. More or less fertile and within neighbouring colonies it is quite common to find both types, fertile and sterile. Apothecia appearing on lower surface at apices of lobes (and consequently the orange to brown-red hymenium corresponds to the lobe lower surfaces and is in reverse position), 0.5-1 cm, reniform or oval, on top of a whitish support ; apothecia brown-reddish, brown-orange, marginate like hoods (lids) only when young. Ascospores brownish, broadly ellipsoid, 3-septate, 16-20 x 5-7 µm. Photobiont: Nostoc. Medulla: K+ purple. Strong maritime trends, on mossy tree trunks, more rarely on mossy rocks where this species is indicative of ancient woodlands. N.B. Look strongly similar to some Peltigera species but the latter do not have apothecia appearing from lower surfaces at apices of lobes. Cf. Nephroma resupinatum K-, of which lower surface is tomentose and has mountain affinity. N.B. Is often a substrate for Degelia plumbea in places where both species occur : see Degelia plumbea vs Nephroma laevigatum. See also the saxicolous form: Nephroma laevigatum forme saxicole.