Plants annual, (1.5–)3–20(–30) cm, sparsely strigulose or gla­brate, hairs basifixed; taproot slender. Stems erect, ascend­ing, decumbent, or prostrate, sparsely strigulose. Leaves 1–6(–7) cm; stipules distinct throughout, triangular or lan­ce­olate, (1–)1.5–5 mm, sub­mem­branous; leaflets (7–)11–17(or 19), blades oblong-, obovate-, or oblanceolate-cuneate, 2–11(–12) mm, apex retuse or emarginate, surfaces glabrous, sometimes hairs present on margins and midrib abaxially. Peduncles erect or divaricate, (2–)2.5–9(–10) cm. Racemes (1 or)2–7(–12)-flowered, flowers spreading to ascending; axis 0–1.2(–2) cm in fruit; bracts 0.8–2 mm; bracteoles 0. Pedicels 0.4–1.7 mm. Flowers (5.2–)8.3–12(–13.2) mm; calyx (3–)3.6–4.5(–5.3) mm, strigulose, tube (1.8–)2–2.4(–2.8) mm, lobes broadly subulate, 1.2–2.2(–2.8) mm; corolla pink-purple, wings often marked with white; banner recurved through 40°; keel (4.5–)6–7.8(–9) mm, apex narrowly acute-triangular, often beak­like. Styles style glabrous. Legumes dehiscent on plant, spreading or ascending, green or purplish becoming brownish then black, straight or slightly incurved, linear or linear-oblanceoloid, 3-sided compressed, (17–)20–37 × 2.2–3.1 mm, slightly fleshy becoming papery, gla­brous; stipe 0 mm or pseudostipe to 0.5 mm. Seeds (17–)20–26. 2n = 26.

Phenology: Flowering Mar–May.
Habitat: Open, oak woodlands, mes­quite thickets, sandy sites.
Elevation: 0–400 m.

Distribution

• Generated Map
• Legacy Map

Ark., La., Okla., Tex.

Discussion

Astragalus leptocarpus occurs in southwestern Arkansas, south-central Louisiana, southern Oklahoma, and eastern Texas. D. Isely (1998) compared it to other Texas annuals in a key with his treatment of A. pleianthus.

Selected References

None.

Lower Taxa

None.