Lomatium triternatum
Lewis' lomatium
(c) Kieran Hanrahan, some rights reserved (CC BY) · licence
Family: Apiaceae · Type: Herb · Native
Lomatium triternatum (Lewis' lomatium) is a native California herb in the Apiaceae family, recognized by . Parent species with varieties listed separately.
Lewis' lomatium is a California native perennial found in open grasslands, rocky slopes, and dry meadows at elevations of 100 to 2,000 meters. Flowering from March to May, this plant produces bright yellow flowers in broad, spreading umbels with 5 to 20 rays. Growing 15 to 100 centimeters tall with a prominent stem and a slender to massive taproot, it has delicate, finely soft-hairy foliage. Its leaves are complex, with intricate 1 to 2 times ternate-pinnate divisions, featuring linear to lance-ovate leaflets 1.5 to 20 centimeters long. The fruit is an elongated structure 6 to 22 millimeters long, with wings typically narrower than the fruit body.
Identification and appearance
Key characters: Geographically isolated. Parent species with varieties listed separately
Habitat and range
California counties: Modoc, Del Norte, Butte, Trinity, Lassen, Siskiyou, Mendocino, Humboldt, Shasta, Nevada, Colusa, Mariposa, Kern, Inyo, Santa Barbara
How to tell it apart
vs Tauschia: Lomatium fruits have prominent marginal wings; Tauschia fruits lack wings or have only slight ribs.; vs Sanicula: Lomatium has typical umbrella-shaped flower clusters; Sanicula has dense ball-like flower heads with hooked bristles.; vs Cymopterus: Lomatium grows upright with a stem; Cymopterus is stemless and grows flat to the ground.; vs Conium: Lomatium grows in dry natural habitats; Conium has purple-spotted stems and grows in moist disturbed areas.; vs Daucus: Lomatium fruits are flat with thin wings; Daucus fruits are cylindrical with spiny bristles.
Frequently asked questions
Is Lomatium triternatum native to California?
Yes. Lomatium triternatum is native to California (recorded as native).
Where in California does Lomatium triternatum grow?
Lomatium triternatum occurs in Modoc, Del Norte, Butte, Trinity, Lassen, Siskiyou, Mendocino, Humboldt and other counties.
What plant family does Lomatium triternatum belong to?
Lomatium triternatum is in the Apiaceae family, genus Lomatium.
Related species
Other California species in the same genus, family, or bioregion.
- Lomatium triternatum var. macrocarpum — Large fruited lewis' lomatium
- Lomatium triternatum var. triternatum — Lewis' lomatium
- Lomatium utriculatum — Bladder parsnip
- Lomatium vaginatum — Broadsheath desertparsley
- Lomatium austiniae — Plummer's lomatium
- Lomatium bicolor var. leptocarpum — Slender fruited lomatium
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.