Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: pendent, flaccid except at the base, 20-40 (-80) cm long, with a persistent base branching: mainly isotomic dichotomous, frequent from the base, axils acute or obtuse, often rounded branches: terete often becoming compressed and angular to foveolate towards the base and at the axils, 0.5-2.0 (-2.5) mm diam. surface: greenish gray to bright golden yellow, sometimes becoming striately blackened in parts; lateral spinules: absent soredia: in irregularly tuberculate soralia, rare in North American material pseudocyphellae: white, abundant, conspicuous, raised, elongate fusiform to ovoid and tuberculate, clearly delimited, usually c. 1 mm long Apothecia: often abundant, lateral; thalline exciple: concolorous with thallus, usually persistent; disc: orange-yellow to dark brown or black, 2-3 (-5) mm in diam., asci: clavate-ovoid, 2-3 (-4)-spored ascospores: ellipsoid, simple, 23-35 (-48) x (12-) 15-20 (-25) µm Pycnidia: sometimes frequent, mainly apical, up to c. 2.0 mm diam., black and shining conidia: not seen Spot tests: cortex K-, C-, KC+ yellow, P-, UV- (sometimes K+ red, C+ green-black near the base); medulla K- (rarely K+ yellow), C- or slowly becoming yellow, KC+ red or KC-, P- (rarely P+ yellow), UV+ ice-blue or UV- Secondary metabolites: cortex with usnic acid, and occasionally an unidentified K+ red, C+ green-black substance; medulla usually with alectoronic acid (major), thamnolic, squamatic and barbatic acids (all accessory) but a common chemotype lacks all secondary metabolites except usnic acid. Substrate and ecology: on a variety of conifers, particularly in moist, lowland forests along the west coast, less often inland World distribution: central and northern Europe, North America and South America (Patagonia) Sonoran distribution: probably extinct, reported from collections in the San Bernardino Mountains of southern California in 1929.