Vascular Plants of North Carolina
Account for Northern Lady Fern - Athyrium angustum   (Willdenow) C. Presl
Members of Athyriaceae:
Members of Athyrium with account distribution info or public map:
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Section 2 » Family Athyriaceae
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Author(Willdenow) C. Presl
DistributionKnown only from several fairly recent collections (1980s to 2015) from the northern Mountains at the highest elevations -- Grandfather Mountain (Avery County) and Roan/Hump Mountains (Avery and Mitchell counties). Specimens from Buncombe County have not been seen by the website editors to determine their validity.

This is a Northern species, ranging from much of Canada south to DE, VA, and MO, and disjunct to northwestern NC and adjacent TN.
AbundanceVery rare, in a rather small area at high elevations (probably only over 5000 feet). This is a Significantly Rare species. Note that NatureServe considers this taxon only as a subspecies, at a Global Rank of G5T5. As Weakley (2018) considers the taxon as a good species, the website editors show the Global Rank of it as [G5].
HabitatThis species grows in cold, rocky habitats in NC, mainly in cracks and crevices of cliffs and rocky summits around the margins of grassy balds; one population is from a boulderfield forest.
PhenologyFruits from June to September.
IdentificationThis species is very similar to Southern Lady Fern (A. asplenioides) and often is considered to be conspecific with it or distinct as the varietal or subspecies level. This species has a stipe about 8-10 inches long and a blade about 12-15 inches long and about 8 inches wide, deeply dissected into a bipinnate-pinnatifid condition. In the other species, the blade is widest at or very near the base, with the lowest 1-2 pairs of pinnae slightly shorter to equal to several above them. However, in A. angustum, the blade is widest well above the base, near the middle, with the fourth or fifth pairs of pinnae from the bottom the longest. Also, in this species the "indusium margins toothed or ciliate, but not glandular; petiole scales persistent, less than 1 cm long and 1.5 mm wide; spores smooth or papillate" (Wofford 1989). The common species has "indusium margins mixed ciliate and glandular-ciliate; petiole scales early deciduous, mostly less than 5 mm long and 1 mm wide; spores reticulate" (Wofford 1989). For all practical purposes, the leaf blade looking widest toward the middle should be a clue to your having this very rare species in the state. Eliminate the similar Hay-scented Fern (Dennstaedtia punctilobula) by that species having rounded sori under the pinnae, as opposed to oblong-linear ones in the Athyrium species.
Taxonomic CommentsMost references name this taxon as A. filix-femina var. angustum or ssp. angustum. Some older ones had it as A. filix-femina var. michauxii.

Other Common Name(s)None. "Lady Fern" is the common name given to the A. filix-femina complex.
State RankS1
Global RankG5T5 [G5]
State StatusSR-P
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