Lomatium howellii
Howell's lomatium
(c) Daniel Kennedy, some rights reserved (CC BY) · licence
Family: Apiaceae · Type: Herb · Native
Conservation status: CNPS 4.3
Lomatium howellii (Howell's lomatium) is a native California herb in the Apiaceae family, recognized by . Key features: large size, dentate leaflets, glaucous herbage.
Howell's lomatium is a California native perennial found in the Klamath Ranges of Del Norte and Siskiyou counties in serpentine chaparral and conifer forest at elevations of 150 to 1,000 meters. Flowering from May to June, this plant produces yellow to purplish flowers in broad compound umbels with 8 to 20 spreading rays. Growing 1.2 to 8 decimeters tall with a stout, branched taproot and glaucous, glabrous stems, it forms an elegant herbaceous presence. Its large, intricately divided leaves are ternate-pinnate to 2-pinnate, with leaflets 1 to 3 centimeters wide, generally obovate and sharply dentate with occasional irregular lobing. The fruit is 6 to 14 millimeters long with wings equal in width to the body, bearing 2 to 3 oil tubes per rib-interval.
Identification and appearance
Key characters: 21 sympatric species. Key features: large size, dentate leaflets, glaucous herbage
Habitat and range
Habitat: Serpentine in chaparral, conifer forest
Elevation: 150-1000 m
California counties: Del Norte, Siskiyou, Tehama, Humboldt, Placer
Outside California: southwestern Oregon
Bloom period
Lomatium howellii blooms May-Jun.
Conservation status
CNPS 4.3
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 howellii native to California?
Yes. Lomatium howellii is native to California (recorded as native).
When does Lomatium howellii bloom?
Lomatium howellii blooms May-Jun.
Where in California does Lomatium howellii grow?
Lomatium howellii occurs in Del Norte, Siskiyou, Tehama, Humboldt, Placer, at elevations of 150-1000 m.
What plant family does Lomatium howellii belong to?
Lomatium howellii is in the Apiaceae family, genus Lomatium.
Is Lomatium howellii rare or endangered?
Lomatium howellii carries California Rare Plant Rank 4.3, state rank S4.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.