Astragalus sinuatus

Plants robust, 20–45 cm, villosulous; from superficial caudex. Stems decumbent to ascending, villosulous. Leaves 2–7 cm; stipules 2–4.5 mm, papery at proximal nodes, herbaceous at distal nodes; leaflets (9 or)11–17(or 19), blades obovate-cuneate or oblong-oblanceolate, (4–)6–16 mm, apex truncate-retuse to obtuse, surfaces villosulous. Peduncles erect or incurved-ascending, 4.5–12 cm. Racemes 8–16-flowered; axis 1.5–4.5 cm in fruit; bracts 2–3 mm; bracteoles usually 2. Pedicels 1.5–3.5 mm. Flowers 16.6–20 mm; calyx 9–11.5 mm, densely villosulous, tube 6.9–8.5 mm, not swollen or gibbous proximally, marcescent, lobes triangular, 1.4–3 mm; corolla whitish, keel tip faintly maculate; keel 12–13.4 mm. Legumes spreading or pendulous, stramineous, lunate- or hamate-incurved, laterally falcately oblong, laterally compressed, 18–30 × (4–)5–7 mm, fleshy becoming leathery, densely villosulous; stipe 5–8 mm. Seeds 24–30. 2n = 22.

Phenology: Flowering mid Apr–Jun.
Habitat: Dry hillsides, among sagebrush.
Elevation: 600 m.

Wash.

Discussion

A similar species, 356. Astragalus asotinensis, differs from A. sinuatus by its straight, appressed calyx pubescence and oblong to narrowly oblong leaflets.

Astragalus sinuatus is restricted to Colockum Creek, Chelan County. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa