Usnea ceratina Ach.
Thallus shrubby, highly ramified, more or less erect at first then pendulous, 30-50 cm long, pale grey-greenish, made of rather unyielding long branches, not blackened at the base (though rather dark in some cases), main branches of uniform diameter with fibrils, 0.5-1 cm long, originating at right angle, and also with tubercles or whitish warts, possibly giving rise to soralia, central axis usually pink (to be observed in cross section and subject to variation: less intense or even absent in old specimen). Apothecia extremely rare, sun-shaped, 1-3 mm diam., disc with few marginal cilia. Photobionte: trebouxioid. C+ golden-yellow to yellow-orange (this is, according to P. CLERC, a distinctive feature, notably on medulla, or in spot test), K-, KC+ yellow-orange (proceed first with C, then add K, the colour should be more intense), Pd-. Rather common in our prospection area, on acid bark of trunks and main branches of old trees in relict woodlands. Richly branched morphs may be confused with Usnea dasypoga / filipendula but the latter is K+ yellow > red and Pd+ orange. Recollect that young Usnea articulata specimen without their 'sausage-like' aspect are rather similar.*