Norw. J. Bot. 23: 159 (1976)
Basionym: Parmelia celastri Sprengel, Car. Linn. Veg., ed. 16, 4, 2: 328 (1827).
Thallus: fruticose, rigid, erect or subpendulous, to 15 cm long, sparingly to moderately branched from an often broad base. Branches stramineous or pale green grey, solid, flattened, lanceolate, plane or somewhat canaliculate, width variable, 1 - 20 mm, commonly 3 - 5 mm, young branches thin, more or less smooth, older branches longitudinally or reticulately ridged from strands of cartilaginous tissue, often holes or cracks. Shortly linear or irregular laminal pseudocyphellae common. Soredia absent. Apothecia numerous, lateral, mainly laminal, stipitate, disc flat or convex, thalline exciple smooth. Spores 11 - 16 / 4 - 7 µm. Pycnidia unknown (Swinscow & Krog 1988: 278).
Photobiont: Data lacking.
Chemistry: No medullary substances, usnic acid in cortex (Swinscow & Krog 1988: 278). Usnic acid (trace only) Alstrup et al. (2010: 347). Usnic acid only (Stevens 1987: 182).
Ecology: Corticolous and lignicolous on trees, shrubs, and posts in natural and artificial habitats in sunny to moderately shady places. In East Africa common and widespread between 800 and 3400 m (Swinscow & Krog 1988: 278).
Distribution Type: Pantropical to pansubtropical.
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