selected vouchers: WTU
Notes: FNA2: "The hybrid Diphasiastrum alpinum X sitchense is very rare. It is known from Greenland, British Columbia, Newfoundland, Montana, Oregon, and Washington. Specimens of D . sitchense from Greenland, Newfoundland, and Washington cited by J. H. Wilce (1965) are actually this hybrid." These hybrids have been documented from a number of locations in the Cascade Mountains of Washington, as well as one location in the Olympic Mountains and one location in the Cascade Mountains of Oregon.