Jepson Flora Project: Jepson Interchange    

link to manual TREATMENT FROM THE JEPSON MANUAL (1993) previous taxon | next taxon
Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



Annual to tree
Leaves generally compound, alternate, stipuled; leaflets generally entire
Inflorescence: generally raceme, spike, umbel or head; flowers sometime 1–2 in axils
Flowers generally bisexual, generally bilateral; hypanthium generally flat or cup-like; sepals generally 5, fused; petals generally 5, free, or the 2 lower ± fused; stamens 1–many, often 10 with 9 filaments at least partly fused, 1 (uppermost) free; pistil 1, ovary superior, generally 1-chambered, ovules 1–many, style, stigma 1
Fruit: legume, sometimes including a stalk-like base above receptacle, dehiscent, or indehiscent and breaking into 1-seeded segments, or indehiscent, 1-seeded, and achene-like
Seeds 1–several, often ± reniform, generally hard, smooth
Genera in family: ± 650 genera, 18,000 species: worldwide; with grasses, requisite in agriculture and most natural ecosystems. Many cultivated, most importantly Arachis , peanut; Glycine , soybean; Phaseolus , beans; Medicago ; Trifolium ; and many orns
Reference: [Polhill & Raven (eds) 1981 Advances in legume systematics; Allen & Allen 1981 Leguminosae]
Family description and key to genera by Duane Isely.


Richard Spellenberg

Annual or perennial herb from crown, glabrous to hairy; hairs sometimes forked at base, branches parallel with leaf surface, sometimes very unequal
Stem 0 or prostrate to erect
Leaves odd-1-pinnate; leaflets generally jointed to midrib; stipules membranous, sometimes fused around stem at stem base
Inflorescence: raceme, axillary, sometimes head- or umbel-like; flowers 2–many
Flower bilateral; calyx 5-lobed; banner outside wings in bud, keel blades with small protrusion at base locking into pit on adjacent wing; 9 filaments fused, 1 free; ovary (and fruit) generally sessile, style slender, stigma minute
Fruit generally 1- or ± 2-chambered, often mottled, generally becoming ± dry; placenta on upper suture
Seeds 2–many, smooth, compressed, ± notched at attachment scar
Species in genus: > 2000 species: ± worldwide (380 in North America, 94 in CA including many rare taxa)
Etymology: (Greek: ankle-bone or dice, perhaps from rattling of seeds within fruit)
Reference: [Barneby 1964 Mem NY Bot Gard 20:1–1188; Isely 1986 Iowa State J Res 61:157–289]
Very difficult; both flower and fruit needed for identification; many good species appear similar; some species complexes need study. Taxa near province boundaries may appear in > 1 key. Varieties keyed under species for simplicity; species with vars. so identified in key. Fr length includes beak and any stalk-like base unless fruit body specified.


A. pomonensis M.E. Jones

Perennial, clumped, leafy
Stem ± ascending, 2.5–8 dm, stout, hollow; hairs 0
Leaf 5–20 cm; leaflets 25–41, 6–30 mm, ± elliptic, thinly strigose on lower surface, sometimes only on midrib
Inflorescence: flowers 10–45, spreading or reflexed
Flower: petals cream, banner 11.1–15.3 mm, recurved ± 40°, keel 9.4–13.2 mm, keel and wing claws 5.1–6.9 mm, keel blade 4.6–6.9 mm, = or < keel claw
Fruit spreading or ascending, deciduous, 18–45 mm, 10–20 mm wide, bladdery, ± ovoid to half-ovoid, ± transparent, papery, sparsely strigose or ± glabrous; chamber 1; immature seeds 34–55
Chromosomes: 2n=22
Ecology: Shrubby, grassy, or weedy areas
Elevation: 50–700 m.
Bioregional distribution: s Outer South Coast Ranges, South Coast, Peninsular Ranges
Distribution outside California: nw Baja California
Like A. douglasii (which has leaflets fewer; keel blade > keel claw).

Information on Fruit width was contributed by Bob Allan (12 Jul 2004):
The width probably should be in millimeters

previous taxon | next taxon
bioregional map for ASTRAGALUS%20pomonensis being generated

Retrieve Jepson Interchange Index to Plant Names entry for Astragalus pomonensis
Retrieve dichotomous key for Astragalus
Overlay Consortium of California Herbaria specimen data by county on this map
Show other taxa with the same California distribution | Read about bioregions | Get lists of plants in a bioregion
Return to the Jepson Interchange main page
Return to treatment index page

University & Jepson Herbaria Home Page |
General Information | University Herbarium | Jepson Herbarium |
Visiting the Herbaria | On-line Resources | Research |
Education | Related Sites
Copyright © by the Regents of the University of California