| Author | (L.) Link | |
| Distribution | Scattered over the Mountains and the northwestern Piedmont -- east to Guilford and Davidson counties. Disjunct east to Wake (historical) and Jones counties (limestone outcrop).
This species ranges widely from east to west. It occurs from NH to Alberta, and south to the FL Panhandle and AZ, but very rare on the Piedmont and Coastal Plain. Also scattered through Mex. to Guat. | |
| Abundance | Uncommon in the Mountains, and quite rare in the northwestern Piedmont, where perhaps extirpated from some counties there, and very rare farther eastward. The species is scarce enough to be considered by the NCNHP as a Watch List species, especially as it seems to have declined in the Piedmont, likely absent now from most counties there. | |
| Habitat | This is another rock-dwelling fern, restricted to crevices in calcareous (primarily) or mafic rocks, seldom on felsic rocks. It prefers dry crevices, typically on limestone; some sites can be somewhat moist, but in general it is found on exposed rocks and not in sheltered grottoes. |
| Phenology | Fruits from May to September. | |
| Identification | This is an evergreen fern, with dimorphic leaves. The fertile leaf is larger, bipinnately dissected blades (at least on the basal pinnae). The dark brown ("purple") stipe averages about 4 inches long, with the blade almost twice as long, to about 6-7 inches long and 2-3 inches wide. There are only 5-11 pairs of pinnae, mostly sub-opposite, each pinna with a stalk of 1/2-inch long, and the pinnules are widely spaced on each pinna, with the upper pinna actually having no pinnules at all. The pinnules on the lower and middle pinnae are very narrow, linear and about 3/4-inch long and barely 1/8-inch wide, with entire margins. The sori are in rows/lines along the edges of the pinnules on the blade undersides, with the edges of the pinnules rolled-under -- as in the Myriopteris species. The sterile leaf has no sori on the undersides of the blades, and is shorter, the blades about 4-6 inches long. The pinnules on the sterile blade are wider, about 3 times longer than wide; in fact, most pinnae are not further divided into pinnules. This species should be easily identified by the narrow and entire finger-like pinnules, which are large and widely spaced, and by the fact that the more terminal pinnae have no pinnules. The more northern P. glabella Mettenius ex Kuhn is known from western VA and eastern TN and may possibly occur in NC on limey cliffs or masonry. Stems and petioles are glabrous (vs. pubescent). | |
| Taxonomic Comments | None
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| Other Common Name(s) | Purple Cliffbrake. This name is about as frequent in usage as is Purple-stem Cliffbrake. As it is the stem (stipe and rachis) this is purple (brown), and not the foliage, Purple Cliffbrake is a misleading name. | |
| State Rank | S3 | |
| Global Rank | G5 | |
| State Status | W1 | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
