Astragalus scopulorum

Plants 15–48 cm, strigulose. Stems decumbent to ascending, 3–13 cm underground, strigulose. Leaves 1.5–8.5 cm; stipules connate-sheathing and stiff-papery at proximal nodes, connate or distinct at distal nodes, 3–9 mm; leaflet blades oblong to elliptic or oblanceolate, some narrowly so, 2–19 mm, apex acute to obtuse or mucronate, surfaces sparsely strigose or glabrous abaxially, glabrous adaxially. Peduncles erect or incurved-ascending, 2–14 cm, shorter or much longer than leaves. Racemes 4–22-flowered; axis 1–7 cm in fruit; bracts 1.5–7 mm; bracteoles 0–2. Pedicels 1–4 mm. Flowers 18–24 mm; calyx 9–11.5(–14) mm, strigulose, tube 6.5–8.5 mm, lobes subulate, 1.5–4(–6) mm; corolla concolorous or keel faintly purplish; keel 13.6–15.4 mm. Legumes green, sometimes also purple, becoming brown, incurved to nearly straight, sulcate abaxially, 18–35 × 3–6.5 mm, papery, glabrous; valves inflexed as complete septum 2–4 mm wide; stipe 4–9 mm. 2n = 22.

Phenology: Flowering May–Aug.
Habitat: Mountain brush, sagebrush, ponderosa pine, pinyon-juniper, and aspen-white fir communities, roadsides, railroads.
Elevation: 1600–3300 m.

Ariz., Colo., N.Mex., Utah.

Discussion

In Utah, disturbance apparently has facilitated the spread of Astragalus scopulorum onto roadcuts, mid-elevation sheep-grazing areas, and along railroads.

Selected References

None.

Lower Taxa