Athyrium angustum
Athyrium angustum is known as the northern lady fern, native to northeastern North America. It was long included in the superspecies Athyrium filix-femina, but is now largely recognized as a distinct species.
Athyrium angustum has a more southern counterpart, Athyrium asplenioides. This species, the southern lady fern, has a broader frond, especially at the base.
