Polystichum dudleyi
Dudley's sword fern
(c) Reid Hardin, some rights reserved (CC BY) · licence
Family: Dryopteridaceae · Type: Herb · Native
Polystichum dudleyi (Dudley's sword fern) is a native California herb in the Dryopteridaceae family, recognized by 2-3 pinnate division and coastal low elevation habitat.
Dudley's sword fern is a California native perennial found in northern coastal and central western California in moist forests at elevations below 500 meters. This fern has a distinctive large, lance-shaped frond reaching 50 to 100 centimeters long with delicate pinnae spreading 5 to 12 centimeters from a slender stipe. Growing with a robust structure, it features a base with ovate scales 3 to 7 millimeters wide and typically forms two-pinnate leaf arrangements. Its fronds are characterized by intricate, finely divided leaflets that create a lush, feathery appearance across forest understories. The fern's sporangia are notably distinguished by cilia-edged indusia, adding textural complexity to its elegant green foliage.
Identification and appearance
Key characters: 6 sympatric species; distinguished by 2-3 pinnate division and coastal low elevation habitat
Habitat and range
Habitat: Moist forests
Elevation: < 500 m
California counties: Santa Clara, Santa Cruz, San Mateo, Humboldt, Monterey, San Luis Obispo, Mendocino, Marin, Napa, Sonoma, San Benito
How to tell it apart
vs Nephrolepis: Polystichum has bristle-tipped teeth and grows in wild habitats; Boston fern has smooth-edged leaflets and escapes from cultivation.; vs Dryopteris: Polystichum fronds feel prickly with bristle-tipped teeth; Dryopteris fronds feel smooth without bristles.; vs Polypodium: Polystichum has shield-shaped spore covers and bristly edges; polypody has naked round spore dots and smooth margins.; vs Struthiopteris: Polystichum has one frond type with bristly teeth; ostrich fern has separate narrow fertile fronds and smooth sterile ones.; vs Athyrium: Polystichum feels prickly and has shield-shaped spore covers; lady ferns feel soft with curved, elongated spore clusters.
Frequently asked questions
Is Polystichum dudleyi native to California?
Yes. Polystichum dudleyi is native to California (recorded as native).
Where in California does Polystichum dudleyi grow?
Polystichum dudleyi occurs in Santa Clara, Santa Cruz, San Mateo, Humboldt, Monterey, San Luis Obispo, Mendocino, Marin and other counties, at elevations of < 500 m.
What plant family does Polystichum dudleyi belong to?
Polystichum dudleyi is in the Dryopteridaceae family, genus Polystichum.
What habitat does Polystichum dudleyi grow in?
Polystichum dudleyi grows in Moist forests.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.