Polypodium calirhiza

Acrid fern

Family: Polypodiaceae · Type: perennial · Native

Acrid fern is a California native perennial found in northwestern California, the Cascade Range foothills, Sierra Nevada, and central western California in rocky habitats on cliffs, outcrops, and roadcuts, often on granitic or volcanic terrain at elevations below 1,400 meters. Its summer-deciduous fronds grow 10 to 20 centimeters long, with oblong-ovate blades that are slightly membranous to firm. The fern features segments with serrated edges and acute to obtuse tips, with a distinctively hairy midrib on the upper surface. Its rhizome is 5 to 10 millimeters in diameter and produces a notably acrid taste when encountered. The plant produces sori (spore clusters) 1.5 to 4 millimeters long, often accompanied by short, branched glandular hairs.

Habitat: On pls, rocky cliffs or outcrops, roadcuts, often granitic or volcanic, rarely dunes

Elevation: < 1400 m

Bioregions: NW (exc NCoRH), CaRF, SN (exc s SNF), GV (rare), CW

California counties: San Francisco, Amador, Butte, Calaveras, Contra Costa, Humboldt, Marin, Placer, Kern, Monterey, El Dorado, San Luis Obispo, Sonoma, Santa Clara, Mariposa, San Mateo, Plumas, Nevada, Fresno, Napa, Santa Cruz, Lake, Tulare, Tuolumne, Solano, Santa Barbara, Sacramento, Sutter, Shasta, Tehama, Mendocino, Alameda, Yuba, Siskiyou, San Benito, Stanislaus, San Bernardino, Los Angeles, Ventura, Yolo

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.