Plants slender, 10–75 cm, stri­gulose; from superficial or sec­ondary subterranean caudex. Stems ascending to erect, strigulose. Leaves (2–)3–11 cm; stipules 3–9 mm, papery proximally, herbaceous distally; leaflets 9–15(or 17), blades elliptic to lanceolate-elliptic or oblong, 1–22(–30) mm, apex obtuse, surfaces strigose abax­ially, glabrous or glabrate adaxially. Peduncles erect or incurved-ascending, (3.5–)5–18 cm, surpassing sub­tending leaf. Racemes (5–)7–27-flowered; axis (1–)3.5–28 cm in fruit; bracts 1–3.5 mm; bracteoles 0(or 1). Pedicels 0.5–2 mm (0.8–3 mm in fruit). Flowers (4.1–)5.5–8 mm; calyx marcescent, 3.3–5.4 mm, strigulose to pilosulous, tube 2.5–3.5 mm, lobes narrowly lance­olate, 0.9–1.6 mm; corolla blue-purple, pale pink, or whitish; keel 4–5.7 mm. Legumes spreading or reflexed, dark when dry, usually somewhat decurved, subsymmetrically or obliquely ovoid-ellipsoid, laterally compressed, (4–)5–12(–13) × (2.3–)2.5–5.5 mm, sub-bilocular, firmly papery, base cuneate, apex shortly cuspidate, strigose-pilosulous; valves inflexed as hyaline septum (0.2–)0.4–1.2 mm wide; sessile or subsessile. Seeds 4–8. 2n = 16, 32.

Phenology: Flowering late May–Aug.
Habitat: Arctic and alpine tundra, heathlands, thickets, woodlands, sandy or gravelly bars and terraces.
Elevation: 0–3300 m.

Distribution

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Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., Nunavut, Ont., Que., Sask., Yukon, Alaska, Colo., Idaho, Maine, Mont., S.Dak., Wash., Wyo., Asia (Russian Far East).

Discussion

Astragalus eucosmus is decidedly closely related to A. robbinsii, and immature fruits are necessary for identification. It is also closely related to the Eurasian A. norvegicus Grauer and might be considered an ele­ment of that species (D. Isely 1998). Plants from the lowlands normally are erect and of moderate stature; at higher elevations and at northern latitudes, dwarf­ing occurs and racemes tend to be shorter and denser. A diploid chromosome number of 16 has been reported from the subsp. sealei variant of this species (G. F. Ledingham 1960).

Selected References

None.

Lower Taxa

None.