Pellaea atropurpurea
Pellaea atropurpurea purple-stem cliffbrake
A unusual wiry fern growing in clumps, widely arching fronds with lustrous purple stipe and rachis, and narrow bluish-green blades. Tends to stay evergreen. It is one of the two species of Pellaea that grow in our area, both are rare, especially the second species, P. glabella. These species are often confused with each other, but can be told apart by the presence of hairs on the stipe and rachis in the purple-stemmed cliffbrake and lack thereof in the smooth cliffbrake.
Habitat & Range
Grows in crevices of dry and exposed limestone cliffs and rocky slopes; sometimes on mortared walls.
Range is from Mexico to Kansas and east to Virginia, north to Michigan and into Vermont.
Wetland code: Not classified
Characteristics
Blade elongated-triangular to lanceolate; variable, with 5 to 11 mostly opposite pinnae; leathery dull blue-green. Shape of the blade is bipinnate.
Pinnae lance-shaped to long and narrow, upper ones undivided, lower ones divided into 3 to 15 pinnules, perpendicular to rachis or angled toward tip of blade; margin inrolled on fertile pinnae (forming false indusium); veins are forked.
Pinnules oval to lanceolate, sometimes with 1 or 2 basal lobes.
Rachis is reddish-purple throughout; short, curly, appressed hairs on upper surface.
Stipe half as long as the blade; dark reddish-purple to almost black; wiry; curly, appressed hairs same as those on the rachis. Hairs may disappear with age.
Rhizome very short, erect or ascending, densely covered by a mass of narrow brown scales.
Sori located beneath margins of fertile pinnae or pinnules ; pale brown. False indusium (margins are rolled on fertile pinnules). Mature by mid-summer.
Plant Codes
S-rank: S4 (Apparently secure)
G-rank: G5 (Secure)
APG/Taxonomization Info
Epithet atropurpurea means 'dark purple' and was recommended by Linnaeus in 1753. Dark purple refers to the color of its stipe.
Pellaea atropurpurea purple-stem cliffbrake
