Lecanora lecideopsis Cl. Roux et C. Coste sp. nov

Description of a new species of lichen, Lecanora lecideopsis Cl. Roux et C. Coste sp. nov., known in a single station of France (department of Hérault, municipality of Mons) on non-calcareous rock (gneiss), which differs differs from Lecanora lecideoides (Nyl.) Harm. by its epithecium green to greenish brown, N + (purple), containing cinereorufa green, its thallus with different chemistry (norstictic acid besides atranorine) and its much narrower, oblong or long ellipsoid spores (10)12–14,4-16(18) x (3)3,5-4,0-4,5(5) µm. Comparison with affine species or analogues. Lectotypification of Lecanora lecideoides, species form which L. rubrofusca should be excluded. Key of determination of Lecanora gr. subfusca of Western Europe, saxicolous, with epithecium without crystals and thallus K + (yellow).