Astragalus thurberi A. Gray
Family: Fabaceae
Thurber's Milk-Vetch,  more...
Astragalus thurberi image
Wiggins 1964, Martin and Hutchins 1980

Duration: Perennial

Nativity: Native

Lifeform: Forb/Herb

General: Annual to short-lived perennial with diffuse stems, decumbent to ascending, 15-40 cm long, herbage appressed-stiff hairs, grayish with striate stems.

Leaves: Pinnate leaves ascending, 3.5-10 cm long, deltoid stipules, 3-5 mm long, about as wide, leaflets 11-17, narrowly elliptic to oblong or linear-oblong, 3-6 mm wide, 8-18 mm long, green, sparsely strigose to glabrate above.

Flowers: Peduncles erect or ascending, 2-12 cm long, striate; racemes compact 2-8 cm long, 10-30 flowered; calyx tube 2-2.2 mm long, finely silvery-strigose, lobes subulate, 1-1.5 mm long; corolla pale yellowish, tinged with purple, 6-7 mm long, banner nearly erect.

Fruits: Sessile, subglobose, 6-13 mm long, abruptly short-apiculate, sparsely appressed- strigose.

Ecology: Found on dry open to rocky slopes and disturbed areas from 3,000-5,000 ft (914-1524 m); flowers March-May.

Distribution: s AZ, sw NM; south to n MEX.

Notes: Distinguished by being a short-lived perennial with stems which branch and have leaves above the ground (caulescent) and are erect to ascending but mostly decumbent; linear to slightly rounded-linear leaves which are mostly hairless above; the densely flowered inflorescences which mostly don-t surpass the leaves; peduncles < 6 cm; a rather small, white-yellowish to purple flower, 6-7 mm long; and the crowded pods which are inflated and nearly globe-shaped.

Ethnobotany: Unknown

Etymology: Astragalus is from Greek astragalos meaning ankle bone and is an early name applied to the genus because of the shape of the seeds, while thurberi is named for Dr. George Thurber (1821-1890) a botanist on the Mexican Boundary Survey of 1850-1854.

Synonyms: None

Editor: SBuckley 2010, FSCoburn 2015