The moss flora of the alpine – high subalpine Chowder Ridge area, western North Cascades Range, Washington State, U.S.A.
Chowder Ridge, a high elevation area near Mt. Baker, Washington State, possesses a moss flora of 77 species based on collections made during two visits. Three species, Dicranum muehlenbeckii B.S.G., Rhacomitrium microcarpon (Hedw.) Brid., and Mnium arizonicum Amann, are reported new to Washington State. Coscinodon calyptratus (Hook.) C Jens. and Grimmia ovalis (Hedw.) Lindb. are noted for the first time from the west slope of the North Cascades. Chowder Ridge harbors an unusually large number of disjunts of the Rocky Mountain interior compared with typical sites on the west slope of the North Cascades, while the Pacific North American element is underrepresented. The bulk of the flora consists of species widespread in western North America.