Oenanthe sarmentosa
Pacific oenanthe
(c) Kieran Hanrahan, some rights reserved (CC BY), uploaded by Kieran Hanrahan · licence
Family: Apiaceae · Type: Herb · Native
Oenanthe sarmentosa (Pacific oenanthe) is a native California herb in the Apiaceae family, recognized by Only New World representative of a primarily Old World genus, at the edge of its range.
Pacific oenanthe is a California native perennial found in coastal and northern California bioregions, including the North Coast, Central Coast, San Francisco Bay Area, and southern California desert regions in streams, marshes, and ponds at elevations below 1,800 meters. Flowering from June to October, this plant produces small white flowers in umbrella-like clusters with 10 to 20 delicate rays. Growing 50 to 150 centimeters tall with branching stems emerging from wet ground, it develops complex two-pinnate leaves with serrated, ovate leaflets. Its leaves are distinctive, with basal leaves having long stalks and an oblong-lanceolate shape, while upper stem leaves become shorter and more triangular-ovate. The plant produces small oblong fruits approximately 3 millimeters long with distinctive wide ribs.
Identification and appearance
Key characters: Only New World representative of a primarily Old World genus, at the edge of its range
Habitat and range
Habitat: Streams, marshes, ponds, generally aquatic
Elevation: < 1800 m
California counties: Humboldt, San Luis Obispo, Monterey, San Mateo, Fresno, Orange, Los Angeles, Del Norte, San Diego, Kern, Mendocino, Santa Cruz, San Bernardino, Riverside, Marin, Alameda, San Francisco, Sonoma, Lake, Solano, Amador, Tulare, Santa Barbara, Madera, Contra Costa, Sacramento, Shasta, Tehama, Santa Clara, Napa, Calaveras, Tuolumne
Outside California: to western Canada
Bloom period
Oenanthe sarmentosa blooms Jun-Oct.
How to tell it apart
vs Sayornis: Sayornis is a bird (flycatcher); Oenanthe is an aquatic plant with white flowers.; vs Sialia: Sialia is a bird (bluebird); Oenanthe is an aquatic plant growing in water.; vs Sium: Oenanthe fruits have a crown of teeth on top; Sium fruits have thick corky ribs but no crown.; vs Berula: Oenanthe has tuberous roots and crowned fruits; Berula has fibrous roots and smooth-topped fruits.; vs Apium: Oenanthe fruits are corky with a persistent crown; Apium fruits are smooth without a crown.
Frequently asked questions
Is Oenanthe sarmentosa native to California?
Yes. Oenanthe sarmentosa is native to California (recorded as native).
When does Oenanthe sarmentosa bloom?
Oenanthe sarmentosa blooms Jun-Oct.
Where in California does Oenanthe sarmentosa grow?
Oenanthe sarmentosa occurs in Humboldt, San Luis Obispo, Monterey, San Mateo, Fresno, Orange, Los Angeles, Del Norte and other counties, at elevations of < 1800 m.
What plant family does Oenanthe sarmentosa belong to?
Oenanthe sarmentosa is in the Apiaceae family, genus Oenanthe.
What habitat does Oenanthe sarmentosa grow in?
Oenanthe sarmentosa grows in Streams, marshes, ponds, generally aquatic.
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.