This species is reportedly a distinct polyploid; 2n = 180 (versus 90 in other Sceptridium species of Ky.), concentrated from the southern Appalachians to the Coastal Plain of La., Miss. and Flo. (FNA 2; K, W).. As summarized by W: "This species probably arose as a hybrid between B. biternatum and B. lunarioides (Michaux) Swartz, followed by polyploidization, resulting in a fertile taxon functioning as a species." S. jenmannii (and S. multifidum) differs from S. dissectum var. obliquum (and S. biternatum and S. oneidense) as follows (W): sterile pinnae entirely divided into short, round or acute pinnules (versus largely elongate, the side often nearly parallel, entre to shallowly lobed but not divided into pinuules); lateral pinnules with an inconspicuous and poorly-developed central vein (versus such a vein); plant producing 1 or 2 leaves per season (versus only one). S. jenmanii was mapped for Ky. in FNA 2,, but no verified colls. have been located. M reported a possible coll. of T.N. McCoy from "Lakeview Church Road" in MARS at MUR in the 1980s. However, McCoy made many colls. of Sceptridium from this locality, and they are all now filed under biternatum or dissectum. Further investigation is needed. The species is reportedly scattered across e. Tenn. (Ch).