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©Copyright 1993 by the Regents of the University of California
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  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

FABACEAE

LEGUME FAMILY

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.

ASTRAGALUS

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.

Native

A. didymocarpus Hook. & Arn.

TWO-SEEDED MILKVETCH

Annual, generally slender, ± minutely grayish strigose
Stem prostrate to ± erect, 3–30 cm
Leaf 0.8–7.5 cm; leaflets 9–17, 2–14 mm, linear to oblanceolate, tips notched
Inflorescence head-like; flowers 5–30, < 9 mm, erect or ascending
Flower: calyx hairs ± mixed black, white; petals whitish, purple-tinged
Fruit ascending, ± included in calyx, 2–4 mm, ± 2 mm wide, ± spheric, 2-lobed in X -section, ± minutely strigose, rarely glabrous, coarsely wrinkled, drying stiffly papery; chambers 2
Ecology: Open grassy, gravelly, or sandy areas
Elevation: 0–1550 m.
Bioregional distribution: c&s Sierra Nevada Foothills, Tehachapi Mountain Area, Great Central Valley, Central Western California, Southwestern California, Desert
Distribution outside California: s Nevada, w Arizona, nw Mexico
Varieties intergrade

Native

var. obispoensis (Rydb.) Jeps.


Stem ascending, 2.5–25 cm; herbage ± grayish hairy
Inflorescence: flowers 5–30
Flower: calyx hairs mostly white, lobes 1–2.5 mm; banner 6.2–8.6 mm, keel 5.2–7.2 mm, crescent-shaped, tip narrowly triangular, acute
Ecology: Grassy hills, openings in chaparral
Elevation: 400–950 m.
Bioregional distribution: Southwestern California except Western Transverse Ranges
Distribution outside California: Baja California

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