Independent Gametophytes of Hymenophyllum wrightii in North America: Not as Rare as We Thought

Hymenophyllum wrightii is a filmy fern known primarily from Japan and Korea. In North America, it is known as a sporophyte only in Haida Gwaii (Queen Charlotte Islands), British Columbia, Canada. Rare independent, filmy fern gametophytes found from the late 1950s and onward at a handful of locations in British Columbia and southeastern Alaska were presumed to be H. wrightii. Our 2006 surveys in southeastern Alaska determined that these gametophytes are common within specific habitats, and our survey in 2008 found gametophyte populations on the Olympic Peninsula in Washington State—the first report of H. wrightii in the contiguous United States. Samples from gametophyte populations from southeastern Alaska, British Columbia and Washington show no variation in rbcL or rps4-trnS sequence and are similar to sequences from Asian H. wrightii sporophytes, providing corroborating evidence of the identity of these independent gametophyte populations.