Adiantum aleuticum

Five-finger fern

Family: Pteridaceae · Type: perennial · Native

Five-finger fern is a California native perennial found in northwestern California, California Mountains, Coast Ranges, San Francisco Bay Area, southern Coast Ranges, northern Channel Islands, Transverse Ranges, and San Jacinto Mountains on shady, moist banks and streamsides at elevations below 3,400 meters. Its distinctive fronds reach 20 to 75 centimeters long with red-brown to nearly black stems, creating a delicate palmate-pinnate blade structure. Growing with an elegant, fan-like form, this fern features pinnules with more than 4 regular lobes, typically cut less than halfway to the midrib. Its pinnule margins converge at a 45 to 90 degree angle, creating an intricate geometric pattern across the frond. Sporangia clusters form 4 to 6 per pinnule, typically less than 3 millimeters wide, highlighting the fern's delicate reproductive structure.

Habitat: Shady, moist banks, streamsides, serpentine

Elevation: < 3400 m

Bioregions: 2/3NW, CaR, SNH, CCo, SnFrB, SCoRO, n ChI, TR, SnJt

California counties: Mendocino, Plumas, Sonoma, Trinity, San Mateo, Placer, Santa Cruz, Siskiyou, Santa Barbara, San Bernardino, Yuba, Riverside, Santa Clara, San Luis Obispo, Los Angeles, Butte, Del Norte, Fresno, Humboldt, Inyo, Madera, Monterey, Nevada, Shasta, Tulare, Tuolumne, Mariposa, Sierra, Amador, Alpine, Marin, El Dorado, Mono, Napa, Tehama, Alameda

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