Astragalus collinus
Gen. Hist. 2: 256. 1832.
Plants clump-forming, robust or slender, 15–40(–50) cm, villosulous; from superficial or shallow subterranean caudex. Stems decumbent to ascending or erect, villosulous. Leaves 3–9(–10.5) cm; stipules distinct, 2–5(–7) mm, papery at proximal nodes, herbaceous at distal nodes; leaflets (9 or)11–21(–25), blades oblong-oblanceolate, narrowly obovate-cuneate, or linear-elliptic, 4–20(–22) mm, apex truncate-retuse to obtuse or retuse, surfaces villosulous abaxially, strigose to glabrescent or glabrous adaxially. Peduncles erect or incurved-ascending, (4–)5–16 cm. Racemes (10–)15–40(–55)-flowered; axis (3–)4–12(–18) cm in fruit; bracts 1.5–3.5 mm; bracteoles 2. Pedicels 0.8–2.8 mm. Flowers (10.5–)12–17.2 mm; calyx campanulate to broadly cylindric, gibbous-saccate, 7–12.3 mm, strigose, tube 5.8–9.4 mm, lobes lanceolate to triangular-subulate or triangular, (0.8–)1–2.7(–3.5) mm; corolla cream to pale lemon yellow; banner usually sigmoidally arched and apex very abruptly and strongly folded over calyx to more than 100°, sometimes recurved through 50°; keel 8.7–13.2 mm. Legumes pendulous, stramineous, straight or gently incurved, linear-oblong or obliquely ovoid-oblong, laterally compressed, 7–25 × 2.3–4.2 mm, somewhat fleshy becoming leathery, usually villosulous or strigulose, rarely glabrous; stipe (3.5–)5–15 mm. Seeds (7 or)8–18.
Distribution
w North America.
Discussion
Varieties 2 (2 in the flora).
D. Isely (1998) remarked that the so-called stubby appearance of the flowers of Astragalus collinus (and of A. curvicarpus var. subglaber, A. gibbsii, and somewhat of A. tweedyi) is compounded by the pouchlike calyx, brief exsertion of the petals, and the sigmoid shape of the shortened banner. Except for A. tweedyi, these taxa could perhaps be considered geographical elements of one species.
Selected References
None.
Key
| 1 | Legumes linear-oblong, 7–25 × 2.5–3.4(–4) mm, usually straight, rarely slightly incurved, villosulous or loosely strigulose, hairs to 0.3–0.5 mm; seeds (10–)12–18; British Columbia, Idaho, Oregon, Washington. | Astragalus collinus var. collinus |
| 1 | Legumes obliquely ovate-oblong, gently incurved, 8–15 × 3.3–4.2 mm, usually villosulous, rarely glabrous, hairs to 0.5–1 mm; seeds (7 or)8–12; Gilliam, Morrow, and Umatilla counties, Oregon. | Astragalus collinus var. laurentii |