Kongel. Norske Vidensk. Selsk. Skr. (Trondheim)1910(1): 45. 1910 ,
North America, Mexico, South America, Europe, Asia, Africa, Pacific Islands (New Zealand), Australia.
This genus is placed in the Ditrichaceae because the chromosome number of n = 13 (E. Lawton 1971) is essentially that of Ditrichum, the type genus of the family. A recent study (M. Stech, unpubl.) supported the relationship between Pseudephemerum and Trichodon, both of the Ditrichaceae.