Acmispon rubriflorus
Red-flowered bird's-foot trefoil, red-flowered bird's-foot trefoil, red-flowered bird's-foot trefoil
(c) Ken-ichi Ueda, some rights reserved (CC BY) · licence
Family: Fabaceae · Type: Herb · Native
Conservation status: CNPS 1B.1
Acmispon rubriflorus (Red-flowered bird's-foot trefoil) is a native California herb in the Fabaceae family, recognized by unique red flowers and shaggy hairs.
Red-flowered bird's-foot trefoil is a rare (CNPS 1B.1) California native annual found in northern Coast Ranges and San Francisco Bay Area regions in oak woodland and grassland at approximately 200 meters elevation. Flowering from April to May, this plant produces pink-red flowers small and delicate with wings approximately equal to the keel. Growing with decumbent to ascending stems 4 to 9 centimeters tall, it has a densely long-shaggy-hairy habit. Its leaves are irregularly pinnate with four lanceolate leaflets 3 to 10 millimeters long, featuring distinctive gland-like stipules. The fruit is a dehiscent, erect pod 8 to 9 millimeters long with a straight, obtuse beak.
Identification and appearance
Key characters: 15 sympatric species; distinguished by unique red flowers and shaggy hairs
Habitat and range
Habitat: Oak woodland, grassland
Elevation: +- 200 m.
California counties: Colusa, Stanislaus, Tehama, Glenn
Bloom period
Acmispon rubriflorus blooms Apr-May.
Conservation status
CNPS 1B.1
How to tell it apart
vs Lotus: Same genus - Lotus is an older name for Acmispon, now considered synonymous.; vs Ottleya: Acmispon has yellow pea-shaped flowers in umbels; Ottleya (a buckwheat relative) has tiny white/pink flowers without pea shape.; vs Eriogonum: Acmispon has compound leaves with 3 leaflets; buckwheats (Eriogonum) have simple leaves.; vs Genista: Acmispon leaves are compound with 3 leaflets; Genista (broom) has simple or very small trifoliate leaves on ridged green stems.; vs Hosackia: Acmispon has tiny gland-like stipules; Hosackia has conspicuous papery or leaf-like stipules at leaf bases.
Frequently asked questions
Is Acmispon rubriflorus native to California?
Yes. Acmispon rubriflorus is native to California (recorded as native).
When does Acmispon rubriflorus bloom?
Acmispon rubriflorus blooms Apr-May.
Where in California does Acmispon rubriflorus grow?
Acmispon rubriflorus occurs in Colusa, Stanislaus, Tehama, Glenn, at elevations of +- 200 m..
What plant family does Acmispon rubriflorus belong to?
Acmispon rubriflorus is in the Fabaceae family, genus Acmispon.
Is Acmispon rubriflorus rare or endangered?
Acmispon rubriflorus carries California Rare Plant Rank 1B.1, state rank S2.
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.