Vascular Plants of North Carolina
Account for Appalachian Rockcap Fern - Polypodium appalachianum   Haufler & Windham
Members of Polypodiaceae:
Members of Polypodium with account distribution info or public map:
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Section 2 » Order Polypodiales » Family Polypodiaceae
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AuthorHaufler & Windham
DistributionThroughout the Mountains and western Piedmont. A few specimens from much farther eastward in the Piedmont to Orange and Lee counties -- if correct. As this species has been pulled out from the former broad sense P. virginianum, the exact details of the ranges of the two are not fully settled.

This is a Northeastern species, ranging from eastern Canada south to NJ, PA, and central OH, south to northern GA and northeastern AL.
AbundanceApparently frequent to common in the Mountains, but rare to uncommon in the western Piedmont. Casual in the central and eastern Piedmont, where poorly known, and nearly all records there refer to P. virginianum.
HabitatThis is a rock-inhabitating species of cool, shaded habitats, as is the very similar P. virginianum. Habitat distinctions between these two seem unclear at the present time, though Weakley (2018) suggests that this species might be more restricted to slightly cooler microclimates, saying "especially in ravines, on north-facing outcrops, and in other moist sites". Nonetheless, you should not attempt to identify these two based on habitat.
PhenologyFruits from June to October.
IdentificationThis species and P. virginianum (strict sense) are extremely similar, with this species recently pulled out from the broad sense P. virginianum. Each is evergreen, with a stipe about 4 inches long and a blade about 6-8 inches long and 2-3 inches wide. The blades are dark green above, glabrous, and pinnately cut. There are 12-20 pairs of pinnae, alternate, finger-like and rounded at the tips, with entire margins. The undersides of the blades are not pocked with numerous dark scales as are the blades of Pleopeltis michauxiana. The sori are rounded and in two rows, one on each side of a pinna midrib on the blade underside. P. virginianum has the "Leaf blade averaging 4.5 cm [nearly 2 inches] wide (range of 3.0-5.8 cm); blade widest near the middle, thus blade oblong to narrowly lanceolate in outline … leaves mostly with an attenuate, unlobed tip". P. appalachianum has "Leaf blade averaging 5.8 cm [about 2.5 inches] wide (range of 3.2-8.2 cm), widest at the base, thus the blade elongate-deltoid in outline … leaves mostly lobed to apex, without an attenuate, unlobed tip".
Taxonomic CommentsSee above.

Other Common Name(s)Appalachian Polypody
State RankS4
Global RankG4G5
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