Plants 3–23(–30) cm, pilosulous; taproot slender. Stems erect to ascending or decumbent, pilo­sulous. Leaves 1–3.5(–4) cm; stipules (1–)1.5–3 mm, submembranous becoming papery; leaflets 7–13(or 15), blades oblanceolate, linear-oblanceolate, or broadly to narrowly cuneate, (1–)2–9 mm, apex retuse, surfaces pilosulous abaxially, pilosulous or glabrate adaxially. Peduncles erect, divar­icate, or incurved-ascending, (1–)2–5(–6) cm. Racemes 4–15-flowered, flowers ascending becoming spreading or declined, curved; axis 0.3–2(–2.7) cm in fruit, elongating; bracts 1.5–1.3 mm; bracteoles 0. Pedicels 0.2–0.9 mm. Flowers 2.5–3.3 mm; calyx 1.8–2.3(–2.5) mm, pilosulous, tube 1.1–1.7 mm, lobes subulate to triangular-subulate, 0.5–0.9 mm; corolla whitish, tinged or veins or margins bluish lilac, sometimes bright violet; keel 2–2.5(–4.2) mm. Legumes deflexed, stramineous or brownish, straight or gently incurved, broadly ovoid, rhombic-ovoid, or subglobose, strongly obcompressed, 2.8–4.2 × 2.4–3.6 mm, thin becoming papery, hirsutulous to strigulose. 2n = 22.

Phenology: Flowering Mar–Jul.
Habitat: Grassy sites, roadsides, chapar­ral, with live oaks, often on serpentine substrates.
Elevation: 10–1300 m.

Distribution

• Generated Map
• Legacy Map

Calif., Oreg., Mexico (Baja California).

Discussion

Astragalus gambelianus and A. didymocarpus are annuals that are superficially similar and sometimes sympatric, with similar dehiscence of the fruits by fracture through both sutures and the septum, the fruit halves separating into two lobes that assume the character of sacs, each containing one proportionately very large seed. Astragalus gambelianus occurs from south-central Oregon to northern Baja California. A. Liston (1992) found the species to be predominantly self-pollinating.

Selected References

None.

Lower Taxa

None.