Astragalus oophorus
Botany (Fortieth Parallel), 73. 1871.
Plants caulescent, 15–30(–40) cm, glabrous or sparsely hairy; from superficial caudex. Stems decumbent to ascending, (2–)15–25 cm, 1 to several internodes elongated and longer than stipules, glabrous or sparsely hairy. Leaves 3–21 cm; stipules 1.5–7 mm, thinly herbaceous becoming papery; leaflets 9–21(–25), blades oval to obovate or orbiculate, 3–20 mm, apex obtuse to retuse or mucronate, surfaces glabrous, ciliate. Peduncles ascending or incurved, 4–13 cm, together with racemes shorter than leaves. Racemes 3–14-flowered, flowers spreading; axis 1–8 cm in fruit; bracts 1.5–5 mm; bracteoles 0–2. Pedicels 2–6 mm. Flowers 11–24 mm; calyx cylindric or campanulate, 6–12 mm, glabrous or sparsely strigulose, tube 4–8.5 mm, lobes subulate, 2–6(–7.7) mm; corolla ochroleucous (concolorous) or pink-purple and wing tips white (bicolored); banner recurved through 85°; keel 9.5–16 mm. Legumes spreading to pendulous, often red-mottled, straight or slightly incurved, ellipsoid, semi-ellipsoid, or semi-ovoid, bladdery-inflated, (20–)25–55(–63) × 10–30 mm, thin becoming papery, glabrous; seed-bearing flange narrow or obsolete, 0.2–0.7 mm wide; gynophore 3.5–11 mm. Seeds 28–54.
Distribution
w United States.
Discussion
Varieties 6 (6 in the flora).
D. Isely (1998) viewed Astragalus oophorus as having two major varieties (var. caulescens to the east, var. oophorus to the west) and several comparatively local, named phases. He noted that A. oophorus was closely related to A. megacarpus and A. beckwithii, but it differs from A. megacarpus by its caulescent habit and usually smaller, more strongly stipitate fruits. From A. beckwithii, it is often distinguished by range, though, technically, it is distinguished by its bladdery-inflated fruit. Variety caulescens and A. beckwithii var. beckwithii co-occur in north-central Utah and, when in flower, are essentially indistinguishable.
Selected References
None.
Lower Taxa
Key
| 1 | Calyces cylindric, tubes 7.8–8.5 × 3.6–4.4 mm; gynophores 10–11 mm; corollas bicolored; se Nevada, adjoining Utah. | Astragalus oophorus var. lonchocalyx |
| 1 | Calyces usually campanulate, tubes 4–7.8 × 2.6–5.5 mm; gynophores 3.5–8(–10.5) mm; corollas white, ochroleucous, or pink-purple and white and bicolored; Arizona, California, Colorado, Nevada, Utah. | undefined |
| null | Shifted for left margin.—Ed.]. | > 2 |
| 2 | Corollas pink-purple, wing tips white, bicolored; legumes subsymmetric, ellipsoid, sutures convexly arched, sometimes less strongly so ventrally; se California, s, wc Nevada. | > 3 |
| 3 | Calyx tubes (4.6–)5–6.5 mm, lobes 2–4.2 mm; corollas 16–23 mm; California and Nevada but not of Spring (Charleston) Mountains. | Astragalus oophorus var. oophorus |
| 3 | Calyx tubes 4–4.3 mm, lobes 2 mm; corollas 11–16 mm; Spring (Charleston) Mountains, Clark and Nye counties, Nevada. | Astragalus oophorus var. clokeyanus |
| 2 | Corollas usually ochroleucous, concolorous, (rarely banners and wings suffused purple); legumes subsymmetric and ellipsoid or asymmetric and semi-ovoid or semi-ellipsoid, sutures subequally concave or gently concave ventrally and straight or strongly convex (in profile); Arizona, California, Colorado, Nevada, Utah. | > 4 |
| 4 | Legumes subsymmetric, ellipsoid, sutures subequally concave (in profile); leaflets 7–11; Mono County, California, wc Nevada. | Astragalus oophorus var. lavinii |
| 4 | Legumes asymmetric, semi-ovoid or semi-ellipsoid, ventral suture gently concave, straight or strongly convex (in profile); leaflets 9–21(–25); Utah plateaus, and nw to ec and s Nevada to n Arizona and w Colorado. | > 5 |
| 5 | Gynophores 5–9 mm; calyces short-cylindric or campanulate, tubes 4.5–6 × 3.3–5.5 mm, lobes 2.3–6(–7.7) mm; n Arizona, ec Nevada, sw, w Utah. | Astragalus oophorus var. caulescens |
| 5 | Gynophores 6–10.5 mm; calyces broadly campanulate, tubes 5.8–7.8 × 5 mm, lobes 3.6–5 mm; w Colorado. | Astragalus oophorus var. wilkenii |