Appalachian Polypody

Polypodium appalachianum is a member of the fern family Polypodiaceae, found across regions including Newfoundland, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saint Pierre and Miquelon, and parts of the United States such as Vermont, Alabama, Connecticut, and others. It is closely related to Polypodium virginianum, which was historically considered a variety of Polypodium vulgare. Research revealed that P. virginianum is an allotetraploid hybrid, with P. appalachianum as one diploid parent and Polypodium sibiricum as the other. The tetraploid form of P. virginianum exhibits a broader climate tolerance than either parent species. This distinction was clarified in 1991, leading to the formal recognition of P. appalachianum as a distinct species.