Plants caulescent, (8–)15–45 cm, strigulose, hairs basifixed; from superficial or barely subterranean caudex. Stems decumbent to ascending, diffuse, leafless basally, strigulose. Leaves 3.5–5.5 cm; stipules 1–6 mm, membranous at proximal nodes, herbaceous with mem­branous margins at distal nodes; leaflets 5–13, blades oblong-elliptic, narrowly oblanceolate, or linear-oblong, 3–12 mm, apex obtuse or obtuse and apiculate, surfaces strigulose, sometimes glabrescent adaxially. Peduncles ascending, 1.2–2.5 cm. Racemes subcapitate, loosely 2–10-flowered, flowers ascending; axis to 1 cm in fruit; bracts 1–5 mm; bracteoles 0–2. Pedicels 0.6–1.5 mm. Flowers (17–)18.1–19.5(–20) mm; calyx cylindric, (9.5–10–11.5(–13) mm, strigose, tube 7–8.2 mm, lobes narrowly lanceolate-subulate, 2.4–4.5 mm; corolla white or whitish, keel maculate; banner incurved through 35°; keel 13.1–13.6 mm. Legumes ascending (humistrate), green, incurved through 0.25–0.5+ spiral, narrowly oblong-ellipsoid or lanceoloid-ellipsoid, dorsiventrally compressed, 25–40 × 8.5–10.5 mm, uni­loc­ular, fleshy becoming subligneous, prominently cross-reticulate, glabrous. Seeds 48–51.

Phenology: Flowering Apr–Jun.
Habitat: Rocky slopes in sagebrush and bunchgrass communities, on basalt.
Elevation: 100–700 m.

Distribution

• Generated Map
• Legacy Map

Loading map...

Wash.

Discussion

Astragalus columbianus, a narrow endemic, is known from only a few kilometers along the Columbia River at Priest Rapids Reservoir in Benton and Yakima counties.

Selected References

None.

Lower Taxa

None.