Atrichum crispulum

Flora of North America (2007) separates the Atrichum oerstedianum of Anderson et al. (1990) into two distinct species: a North American/East Asian species (Atrichum crispulum) and a Mexican/Central American species (Atrichum oerstedianum s.s. - excluded). Flora of North America notes that "in recent North American literature [A. crispulum] has been called A. oerstedianum, but comparisons with the type of A. oerstedianum indicate that the two are distinct"; morphological differences between the species are then described. The name "Atrichum crispulum" is not addressed by Anderson et al. (1990).