Usnea rubicunda forme fertile.
Usnea rubiginosa auct. non (Michx.) A. Massal.
Rare, differs from the type mostly by its apothecia, 3-6 mm diam, papyraceous, disc concave to plane, pale grey-greenish to whitish, sometimes very pale brown-pinkish, exciple with minute concolourous (to the thallus) fibril buds, more seldom with radiating minute fibrils. In addition thallus branches have less isidiomorphs than the much more common sterile type. Ascii 8-spored, utriform, 45-60 x 15-18 µm according to our measures. Ascospores broadly ellipsoid, colourless, simple, (7) 8-10 x 5-6 (7) µm according to our measures. Very rare fertile form, on twigs of more or less dead trees and bushes near the seashore, together with the sterile form, also on trunks or large branches. N.B. Identification confirmed for all by P. CLERC. See also Usnea ceratina et Usnea subfloridana that may be fertile but devoid of reddish tinge.