Melanohalea
Type : Melanohalea exasperata (De Not.) O.Blanco, A.Crespo, Divakar, Essl., D.Hawksw. & Lumbsch [=Parmelia exasperata De Not.]
Description : Thallus foliose, loosely to moderately adnate. Lobes plane to concave, flat, short, apices rounded, 0.5–7 mm wide, eciliate. Upper surface olive-green to dark-brown, smooth to wrinkled, emaculate, commonly pseudocyphellate, with or without isidia or soredia. Pseudocyphellae white, on warts or on tips of isidia; upper surface paraplectenchymatous, 10–16 μm thick, epicortex not pored (SEM); cell walls containing isolichenan. Medulla white. Photobiont green, trebouxioid. Lower surface of plant smooth, pale-brown to black; rhizines simple. Ascomata apothecia, laminal, sessile to subpedicellate; disc imperforate, concave and becoming convex with age, brown; ampithecium with pseudocyphellate papillae, emaculate. Asci elongate-clavate, Lecanora -type, apically thickened, without an internal, apical beak, 8–32-spored. Ascospores globose to ovoid or ellipsoidal, thin-walled, colourless, 5.5–20 × 4–12.5 μm. Conidiomata pycnidia, immersed, laminal. Conidiophores of type V or VI (Vobis 1980). Conidia cylindrical to fusiform, simple, colourless, 5–8.5 × 1 μm.
Melanohalea, a genus of c. 19 accepted species (Blanco et al. 2004a) in the Parmeliaceae that have their primary distribution on bark and wood in the Northern Hemisphere, with three species known from the Southern Hemisphere two of which are found in New Zealand. The genus is characterised by: pseudocyphellae, usually on warts or tips of isidia, a non-pored epicortex, a cortex containing brown pigments, and a medulla containing depsidones (fumarprotocetraric or norstictic acids) or lacking secondary compounds.
