About Athyrium angustum (Willd.) C.Presl
Athyrium angustum, commonly known as the northern lady fern, is a fern species native to northeastern North America. For a long time, it was classified as part of the superspecies Athyrium filix-femina, but it is now widely recognized as a separate distinct species. The very similar southern lady fern, Athyrium asplenioides, is the more southern counterpart of Athyrium angustum. Athyrium asplenioides has broader fronds, particularly at the base, than Athyrium angustum.
