Astragalus scaphoides
Mem. New York Bot. Gard. 1: 241. 1900. (as scophioides)
Plants 15–40 cm, strigulose, hairs basifixed; from subterranean branched caudex. Stems decumbent to erect, strigulose. Leaves (6–)8–20(–24) cm; stipules 3–8 mm, submembranous early becoming papery; leaflets (9–)17–25, blades oblong, elliptic, rhombic-ovate, or rhombic-lanceolate to linear-elliptic, (7–)10–20(–28) mm, apex obtuse to subacute, surfaces strigulose abaxially, glabrous adaxially. Peduncles erect, 8–16 cm. Racemes (9–)15–30-flowered, flowers spreading to nodding; axis (3–)5–17 cm in fruit; bracts 2–4.5 mm; bracteoles 2. Pedicels 1.5–5 mm. Flowers 18.5–20.5 mm; calyx short-cylindric, 9.6–12.2 mm, strigulose, tube 7–9 mm, lobes triangular to subulate, (1–)2–3.2 mm; corolla ochroleucous, immaculate; banner recurved through 50°; keel 13–15 mm. Legumes erect, green, sometimes suffused or speckled with purple, becoming stramineous, straight or nearly so, subsymmetrically oblong- or ovoid-ellipsoid, moderately inflated, obcompressed, both sutures grooved, 11–22 × (4.5–)6.5–10 mm, base truncate, ± bilocular, fleshy becoming leathery, glabrous; septum 1.4–1.8 mm wide; stipe 12–18 mm. Seeds 21–32.
Phenology: Flowering Jun–early Aug.
Habitat: With sagebrush, on limestone or basalt soils.
Elevation: 1000–1900 m.
Discussion
Astragalus scaphoides, found in the Bitterroot Mountains, Beaverhead County, Montana, and adjacent valleys of the upper Salmon and Lemhi rivers, Lemhi County, Idaho, appears much like a rather coarse version of A. eremiticus at anthesis. The thick fruit, truncate at the base, is diagnostic.
Selected References
None.