Athyrium distentifolium var. americanum
American alpine lady fern
Family: Athyriaceae · Type: perennial · Native
American alpine lady fern is a native perennial found in the Klamath Ranges, California High Cascade Range, Sierra Nevada, Warner Mountains, and White and Inyo Mountains in moist or wet rock crevices, talus, cliffs, boulder bases, and streamsides at elevations of 1,700 to 3,700 meters. While not producing flowers, this delicate fern is characterized by its distinctive leaf structure. Growing with narrow, elegant fronds that can reach substantial heights, the fern develops complex multilayered leaves with intricate pinnate divisions. Its leaf blades are narrow-elliptic or lanceolate, intricately divided into 2 to 3 pinnate layers, with lower pinnae pairs slightly shorter than those above and ultimate segments showing shallow to deep pinnate lobing. The fern's midribs are notably glabrous or sparsely scaled, creating a refined and delicate botanical texture.
Habitat: Moist or wet rock crevices, talus, cliffs, boulder bases, streamsides
Elevation: 1700-3700 m
Bioregions: KR, CaRH, SNH, Wrn, W&I
California counties: Mono, Tulare, Butte, Sierra, Nevada, Siskiyou, Tehama, Inyo, Alpine, Tuolumne, El Dorado, Shasta, Mariposa, Madera, Placer, Fresno, Plumas, Modoc, Trinity, Del Norte
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.