Observ. Bot.,34. 1803 ,
North America, Mexico, West Indies, Central America, s South America, Europe, Asia, Atlantic Islands (Azores, Madeira), Pacific Islands, Australia.
Species 12 (2 in the flora).
Diphyscium is the most widespread genus in the family and is mainly temperate to subtropical. It is sufficiently distinctive and unlikely to be confused with any other genus in North America if perichaetia or sporophytes are present. Vegetative material is superficially similar to that of the Pottiaceae, especially in leaf form and papillosity. Fortunately, perichaetia and sporophytes are frequent in the eastern range of the genus, while turf firmly cemented by rhizoids is a trait not shared by Pottiaceae in the same range.