Flora of New Zealand Series

Thallus fruticose, radial, ± flattened, erect or decumbent, ± richly to sparsely branched or entangled, rather fragile when dry, terricolous or muscicolous. Photobiont green, Trebouxia. Medulla white, filling branches. Apothecia lecanorine with an entire, toothed or spinose thalline margin. Ascospores colourless, simple, ellipsoid, 8 per ascus.

Coelocaulon, included in the family Usneaceae, is a temperate, alpine, predominantly boreal genus although some species are truly bipolar, e.g., C. aculeatum, which occurs in cushion vegetation on the mountains of southern New Zealand. It is frequently found associated with other bipolar genera such as Alectoria, Brigantiaea, Cetraria, Pseudephebe and Solorina.