Family: Dryopteridaceae
MacKay's brittle fern, upland brittle bladder fern
[Cystopteris fragilis var. mackayi (L.) Bernh., more...]
Robert W. Freckmann
Robert W. Freckmann
University of Wisconsin - Madison (WIS-VP)
Etymology: Cystopteris: from Greek cystis, "bladder," and pteris, "fern"
Plants: perennial fern
Habitat: moist rocky crevices
Conservation Status: Native
Plants: perennial fern
Habitat: moist rocky crevices
Conservation Status: Native
On moist shaded rock outcroppings, especially sandstone, on cliffs, and sometimes on humus-rich forest soil. This species closely resembles C. fragilis and was included in that species as var. mackayi G.Lawson in older treatments. Plants with pinnae angled upward and curved toward the apex of the blade are obviously C. tenuis, but many specimens lack this feature. The rounded teeth on the pinnae and the nearly equal number of veins ending in the notches rather than the teeth help separate this species from C. fragilis when pinnae are perpendicular to the rachis. Hybridization with C. bulbifera produces the sterile triploid C.X illinoensis R.C.Moran.
Flora of North America: Flora of North America Floristic Rating: Coefficient of Conservatism = 10 USDA Plants Database: Federal Distribution and detailed information including photos University of Wisconsin - Green Bay: Fern & Fern Allies: Photos, descriptions, information
Robert W. Freckmann
