Leptogium cyanescens (Rabenh.) Körb.
Collema cyanescens Rabenh., Dtsch. Kryptfl. 2: 50 (1845).
Leptogium rigens Nyl., Annls Sci. nat. Bot. sér. 4, 15: 368 (1861).
L. rigens. Lectotype: New Zealand, D'Urville ex Herb. Buchinger, H-NYL 41335!
Thallus lobate, flat, attached loosely to substrate by scattered tufts of hairs, spreading, orbicular to irregular, 1-5(-8) cm diam., greyish-blue to olive greenish, corticolous. Lobes orbicular, 2-4 mm wide, margins entire, wavy, ± ascending to dentate-isidiate. Upper surface smooth to occasionally slightly roughened, not wrinkled or plicate, isidiate. Isidia abundant, laminal, granular-furfuraceous, cylindrical to clavate to lobulate, often branching, concolorous with thallus. Lower surface glabrous, smooth, concolorous with upper surface or paler, to ± greyish-fawn. Apothecia rare, sessile, to subpedicellate, laminal, 0.5-2 mm diam., disc concave to convex, pale brown to red-brown, thalline exciple entire to isidiate, pale grey to fawn. Ascospores ellipsoid, apices rounded or pointed, 18-27 × 6-10 µm.
N: North Auckland to Wellington. S: Nelson to Fiordland. Widespread on bark and twigs in moderate to deep shade. L. rigens Nyl. is a thicker, rather more coriaceous form of L. cyanescens.
Cosmopolitan
