Polypodium hesperium
Western polypody
(c) Jason Hollinger, some rights reserved (CC BY) · licence
Family: Polypodiaceae · Type: Herb · Native
Polypodium hesperium (Western polypody) is a native California herb in the Polypodiaceae family, recognized by high elevation habitat and unique dark, shriveled sporangia mixed in sori.
Western polypody is a California native fern found in the Klamath Ranges, northern and central Sierra Nevada, San Bernardino Mountains, San Jacinto Mountains, White and Inyo Mountains, and eastern desert mountains including the New York Mountains in rock crevices and talus slopes at elevations of 1,400 to 2,980 meters. Its large oblong to oblong-ovate fronds range from 2 to 25 centimeters long, with segments that are either entire or minutely serrate and typically have obtuse to acute tips. Growing with a rhizome 3 to 6 millimeters in diameter, this fern can have white-glaucous or plain rhizome scales that may show a slightly darker central area. Its leaf blades are membranous to firm, with free veins and a glabrous midrib on the upper surface. The sori are round to ovate, measuring 1 to 2.5 millimeters and containing up to 5 dark brown or red-black sporangia.
Identification and appearance
Key characters: 3 sympatric species; distinguished by high elevation habitat and unique dark, shriveled sporangia mixed in sori
Habitat and range
Habitat: rock crevices, talus slopes, under rock ledges
Elevation: 1400-2980 m
California counties: San Bernardino, Placer, Riverside, Fresno, Mono, Los Angeles, Santa Barbara, El Dorado, Tuolumne, Trinity, Mariposa, Siskiyou, Humboldt, Ventura
Outside California: to British Columbia, Rocky Mountains, northern Mexico
How to tell it apart
vs Polystichum: Polypodium sori are completely naked; Polystichum sori have umbrella-like covers attached at the center.; vs Dryopteris: Polypodium sori lack any covering; Dryopteris sori have kidney-shaped covers attached at the side.; vs Pentagramma: Polypodium sori are on the upper leaf surface; Pentagramma has powder on the lower leaf surface.; vs Pteridium: Polypodium sori are round and exposed; Pteridium sori are hidden under rolled-back leaf margins.; vs Woodwardia: Polypodium has round sori; Woodwardia has elongated chain-like sori in parallel rows.
Frequently asked questions
Is Polypodium hesperium native to California?
Yes. Polypodium hesperium is native to California (recorded as native).
Where in California does Polypodium hesperium grow?
Polypodium hesperium occurs in San Bernardino, Placer, Riverside, Fresno, Mono, Los Angeles, Santa Barbara, El Dorado and other counties, at elevations of 1400-2980 m.
What plant family does Polypodium hesperium belong to?
Polypodium hesperium is in the Polypodiaceae family, genus Polypodium.
What habitat does Polypodium hesperium grow in?
Polypodium hesperium grows in rock crevices, talus slopes, under rock ledges.
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.