Synonyms: Lendemeriella sorocarpa (Vain.) S. Y. Kondr.
Distribution: N - Frl (vidi!), TAA (Hinteregger 1994).
Description: Thallus crustose, continuous, areolate or warted, rather thin, greenish white to greenish grey or grey, often delimited by a dark prothallus, with numerous, perfectly circular, (0.1-)0.25-0.5 mm wide, at first immersed, then protruding to almost stipitate, whitish to greenish grey soralia which are often surrounded by a whitish, thin thalline rim. Apothecia extremely rare, 0.2-0.3 mm across, at first immersed, then sessile, with a concave to flat, orange to red-brown, rough disc, a thin proper margin, and sometimes a poorly developed thalline margin. Proper exciple brownish in outer part, colourless within, of radially arranged hyphae, sometimes overlain by a paraplectenchymatous thalline exciple in lower part; epithecium reddish orange, K+ red, with a granulose epipsamma; hymenium colourless, 70-80 μm high; paraphyses simple or rarely sparingly branched, not or slightly swollen at apex (2-3.5 μm thick); hypothecium colourless. Ascospores 1-septate, polarilocular, hyaline, ellipsoid, 8-15 x 5-8 μm, the septum 2-4.5 μm thick. Pycnidia rare, orange to red-brown. Conidia bacicilliform, 4.5-6 x c. 1 μm. Photobiont chlorococcoid. Spot tests: thallus and soralia K-, C-or C+ pale yellow (soralia only), KC-, P-; apothecial disc K+ red. Chemistry: apothecia with different anthraquinones.
Note: a usually sterile lichen with a grey thallus and concolorous, circular, often raised soralia; easily overlooked, it is one of the most common sorediate crusts growing on the branches of Rhododendron. The species, which is included in the Italian red list of epiphytic lichens as “Critically Endangered” (Nascimbene & al. 2013c), is closely related to C. exsecuta (Vondrák in litt.).
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)