Hypotrachyna lueckingii Sipman  

Mycobank MB 517783

Thallus foliose, corticolous, 5–10 cm wide, loosely adnate, not coriaceous, dichotomously to subdichotomously lobate. Lobes sublinear to subirregular, mostly separate, (0.5–)1.5–3 mm wide, plane to slightly convex, with subtruncate apices. Upper surface greenish yellow, slightly shiny, epruinose, emaculate, lacking soredia, isidia, pustules, dactyls or lobules, and with intact upper cortex. Medulla white, with a continuous algal layer above. Lower surface black, peripherally dark brown. Rhizines black, rather dense, sometimes forming a marginal fringe, ca. 0.5 mm long, 1–4 times dichotomously branched. Apothecia frequent, 2–7 mm in diam., with concave, finally flat, brown, glossy discs and crenulated, incurved margins. Ascospores ellipsoid, 10–13 x 6–7 µm. Pycnidia frequent, laminal, immersed. Conidia weakly bifusiform, ca. 6 x 0.5 µm. Chemistry: upper cortex K–, C–, KC+ yellow, P–, UV–, medulla K–, C–, KC–, P+ orange-red, UV–. Secondary metabolites: upper cortex with usnic acid (major), medulla with protocetraric acid (major) and gyrophoric acid (minor).