Acmispon argophyllus
Silver birds foot trefoil
Photo by Chez Brungraber
Family: Fabaceae · Type: Subshrub · Native
Acmispon argophyllus (Silver birds foot trefoil) is a native California subshrub in the Fabaceae family, recognized by silvery indumentum and indehiscent fruits.
Silver birds foot trefoil is a California native perennial found in coastal and southern California chaparral and coastal sage scrub habitats. Flowering from March to June, this plant produces yellow flowers in small head-like clusters with 4 to 15 blossoms. Growing with prostrate to erect stems 10 to 60 centimeters tall, it has a somewhat woody base covered in fine, silvery-gray hairs that give the plant a soft, silky appearance. Its leaves are irregularly pinnate with 3 to 7 obovate leaflets 6 to 12 millimeters long, densely covered with hairs that almost completely obscure the leaf surface. The fruit is a curved, half-ovate pod with a small 2 to 3 millimeter curved beak.
Identification and appearance
Key characters: 36 sympatric species; distinguished by silvery indumentum and indehiscent fruits
Habitat and range
California counties: Tulare, San Bernardino, Monterey, Nevada, Santa Barbara, San Diego, San Luis Obispo, Kern, Riverside, Los Angeles, Fresno, Imperial, Ventura, El Dorado
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 argophyllus native to California?
Yes. Acmispon argophyllus is native to California (recorded as native).
Where in California does Acmispon argophyllus grow?
Acmispon argophyllus occurs in Tulare, San Bernardino, Monterey, Nevada, Santa Barbara, San Diego, San Luis Obispo, Kern and other counties.
What plant family does Acmispon argophyllus belong to?
Acmispon argophyllus is in the Fabaceae family, genus Acmispon.
Related species
Other California species in the same genus, family, or bioregion.
- Acmispon argophyllus var. adsurgens — San clemente island bird's-foot trefoil
- Acmispon argophyllus var. argenteus — Channel Islands silver lotus
- Acmispon argophyllus var. argophyllus — Southern California silver lotus
- Acmispon argophyllus var. fremontii — Fremont's silver lotus
- Acmispon argophyllus var. niveus — Santa cruz island bird's-foot trefoil
- Acmispon argyraeus — Canyon birdsfoot trefoil
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.