Chaenotheca trichialis (Ach.) Th. Fr.
Calicium trichiale Ach.
Thallus superficial, usually rather thick, crustose, squamulose to granulose, composed of minute granules and/or squamules, green-greyish, green-yellowish, green tinged blue. Apothecia stalked and capitate, 1-2.5 mm high; stipe 1-2 mm high (sometimes shorter and vanished in case of very thick thallus), dark brown to blackish, apex powdery, white. Capitulum subspherical to sunconical, sometimes lenticular, 0.2-0.4 mm diam., with whitish cottony hyphae towards the base, smooth at first becoming hairy and then Trichia (Myxomycete)-like, dark brown, brown. Ascii string forming, shortly cylindrical, 1-(2)-spored, 11-14 x 2-2,5 µm. Ascospores globose, 4-5 µm diam.. Photobiont: Stichococcus (Cells: narrowly oval with parietal chloroplast). Thallus: C-, K-, KC-, Pd-. Rare or understated. On acid bark of trees in humid and temperate woodlands, often in cracks and holes; in our prospection area, seems resricted to the north face of Pinus in humid areas. See Chaenotheca brunneola, rather similar but of which the thallus is more encrusted in bark, Pd+ yellow turning orange. N.B. Rather variable species that would include several cryptospecies. N.B. Sterile thalli of Psilolechia lucida may be mistaken but this species is saxicolous. Not to be confused with Chrysothrix candelaris that usually grows on pine bark, but most often is golden yellow.*