Psoroma angustisectum
Description : Thallus of scattered squamules, in irregular patches to 3 cm diam. Squamules pale yellowish brown, often blackened at base, narrow, 0.25–0.5 mm wide, deeply incised, apices distinctly coralloid, terete, ascending, corticate, to 200 μm thick, with a distinct paraplectenchymatous cortex, 30–40 μm thick. Cephalodia similar to normal squamules but darker, containing Nostoc. Apothecia rare, not well-developed, to 3 mm diam.; disc plane, brown, without sterile tissue; thalline margin prominent, concolorous with thallus. Hymenium I+ blackish blue. Asci broadly clavate, apically thickened with a distinct, amyloid internal ring-structure. Ascospores colourless, ellipsoidal, 25–35(–38) × 10–15 μm, distinctly warted. Pycnidia not seen.
Chemistry : two unidentified pigments.
A: (Adams I.). On mosses in subalpine habitats; collected by Prof. Henry Imshaug (MSC). Known also from Juan Fernandez (Zahlbruckner 1924; Jørgensen 2003c).
Austral
Illustration : Zahlbruckner (1924: tab. 25, fig. 3).
Psoroma angustisectum is characterised by: the muscicolous habit; the thallus of narrow, deeply incised squamules, with terete, coralloid, ascending apices; and ascospores 25–35(–38) × 10–15 μm, with a warted perispore.
