Cladonia grayi G. Merr. ex Sandst. Cf.

    Primary thallus made of small squamules, up to 5 mm high, slightly incised, green-blue, green-gray, podetia cup-shaped, with sometimes minute squamules at the basis, 1-2.5 mm high, covered with finely verrucose soredia inside and out, grayish-green in humid weather, grayish in dry weather with a purple to purplish margin, possibly extending to the whole scyphus, pinkish-brown medulla. Apothecia brown, more or less stipitate, at scyphus margin as well as brown pycnidia. Thallus : C-, K-, KC-, Pd- or Pd+/- red, UV+ mauve (which would be a good distinctive character) Rare (?), on sandy soils of very acid heathlands enriched in ligneous debris and sometimes on dunes. This species belongs to a complex of several taxa and our presentation is done with the usual restrictions since the current knowledge makes difficult to clearly discriminate our specimen from the others. It is also difficult to distinguish from other close species; the main distinctive hallmarks are summurized as follows:

_ Cladonia chlorophaea : Scyphus indented and soredia minutely granular;

_ Cladonia grayi complex : Scyphus with soredia verrucose, fairly dark and grayish and a purple to purplish margin.

_ Cladonia pyxidata : Scyphus covered with squamules-like granules notably inside the cup.