Usnea longissima

Usnea longissima is restricted to boreal coniferous regions where it has an incompletely circumpolar distribution, with occurrences in Europe, Asia, North America (Motyka 1936-38, Ahti 1977a) and Africa (by Tuckerman 1848, as reported in Keon 2001). It has been collected from mountains in China, India, Canada (British Columbia, Quebec, and Ontario), Indonesia, Europe (Scandinavia and Spain) and the USA (Alaska, far north western, and New England states). The distribution was previously considered to be continental (Ahlner 1948, Gams 1961); from oceanic parts of Norway (Jorgensen & Ovstedal 1975, Gauslaa et al. 1992), and from the USA the species is more common near coasts (Ahti 1977a, Esseen et al. 1981). It has been reported from slopes above 3200 m in the Hengduan Mountains, above 3800 m in the greater Liangshan Mountains in southwestern Sichuan province, and also above 2200 m at the western edge of the Sichuan basin, China. It has also been collected from the Simla Mountains of India. In the USA, the range is disjunct and includes Alaska to California and west of the Cascade Range crest (www.fs.fed.us) and the New England states, Massachusetts, Maine, New Hampshire and Vermont (members.aol.com; see web citations). The distribution in Scandinavia was mapped by Ahlner (1948) and updated distribution data are given by Esseen & Ericson (1982), Esseen (1991), and Andersson & Williamson (1993).