Annual to usually perennial from a simple or branched caudex. Herbage strigose with dolabriform hairs. Stems erect to ascending, 1–3 cm, shorter than the mostly basal leaves. Leaves with 5–15 linear-elliptic leaflets with acute tips; stipules lanceolate, 2–5 mm long, distinct. Inflorescence nearly sessile with 2–8 spreading flowers, shorter or longer than the leaves. Flowers ochroleucus; calyx white-strigose; sepals 2–4 mm long; banner 9–11 mm long, nearly straight; keel 6–8 mm long. Legume narrowly ellipsoid, beaked, inflated, compressed perpendicular to the septum, 15–25 mm long, densely silky (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Low Milkvetch -
Astragalus lotiflorus*Leaves with 5–15 linear-elliptic leaflets with acute tips.
*Leaf stipules lanceolate, 2–5 mm long, and distinct.
*Flowers are arranged in almost sessile racemes with 2–8 spreading flowers.
*Flowering stems are shorter than the leaves.
Wind River Milkvetch –
Astragalus oreganus, SOC
*Stems zigzag. 10-20 cm tall.
*Leaves have 5-15 broadly elliptic to nearly round leaflets (obovate) with blunt to rounded tips, and 2-forked hairs (dolabriform).
*Leaf stipules form a papery sheath at the base of each petiole, completely surrounding the stem (connate), 5-10 mm long.
*Flowers are yellowish-white (ochroleucus), 15-40, crowded in racemes, and cylindrical.
*Flowering stems are barely longer than the leaves.
Canadian Milkvetch -
Astragalus canadensis*Stems do not zigzag, 15-60 cm tall.
*Leaves have 11-23 narrowly elliptic leaflets.
*Leaf stipules are lanceolate-attenuate, 5-10 mm long.
*Flowers 30-100 spreading to declining in crowded racemes.
POLLINATORS The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap:
Bombus vagans,
Bombus appositus,
Bombus auricomus,
Bombus bifarius,
Bombus borealis,
Bombus centralis,
Bombus fervidus,
Bombus flavifrons,
Bombus huntii,
Bombus mixtus,
Bombus nevadensis,
Bombus rufocinctus,
Bombus ternarius,
Bombus terricola,
Bombus occidentalis,
Bombus pensylvanicus,
Bombus griseocollis, and
Bombus insularis (Macior 1974, Thorp et al. 1983, Mayer et al. 2000, Colla and Dumesh 2010, Wilson et al. 2010, Koch et al. 2012, Miller-Struttmann and Galen 2014, Williams et al. 2014).
