Galapagos Species Database

Thallus shrubby, greenish grey, decaying parts becoming red, without a distinct holdfast, relatively densely branched, up to 15 cm diam., but usually much smaller (3-7 cm); branches initially upright, hanging down when older, in most parts distinctly canaliculate and in section broadly crescent-shaped to±flattened, sometimes also markedly curved in the longitudinal direction and frequently with curved lobe tips (“shepherds' crooks”), slender to relatively broad (up to 15 mm wide), occasionally anastomosing, leaving oval to elongated holes; lobe margins with rounded, irregular warts from which irregular, punctiform or sublinear pseudocyphellae develop; soralia absent. Apothecia common, c. 2–7 mm diam., cupular, laminal to subterminal; disc yellowish to pinkish grey; branches often bent at the apothecia (geniculate), verrucose below with crateriform pseudocyphellae; ascospores hyaline, 1-septate, narrowly oblong, usually ±curved, 10-12 x 4–5 µm. Pycnidia mostly marginal, hemispherical, 0.1–0.2 mm diam., ostiole pale ochre; conidia rod-shaped, 5–6 x 0.5–1.0 µm. Chemistry: Medulla K+ orange yellow, soon red, UV+ white or UV- (salazinic, sekikaic, divaricatic acid); cortex with usnic acid, occasionally (e.g. in the type collection) also with atranorin.

The species is similar to R. complanata, which, however, has an irregularly flattened, not distinctly canaliculate surface and laminal tuberculate pseudocyphellae. Ramalina sideriza is also vaguely similar in habitus and as with R. darwiniana has hooked lobe tips, but it has flattened lobes with a distinctly striate, often coarsely linear pseudocyphellate surface.