Astragalus gibbsii
Proc. Calif. Acad. Sci. 2: 161, fig. 50. 1863.
Plants stout, 15–35 cm, villosulous; from slightly subterranean caudex. Stems decumbent to prostrate, 5–8 cm underground, villosulous. Leaves (1.5–)3–9.5 cm; stipules connate-sheathing and scarious at proximal nodes, distinct and herbaceous at distal nodes, 1.5–5 mm; leaflets (7–)11–19, blades broadly or narrowly cuneate, obovate-cuneate, or oblanceolate, 4–20 mm, apex retuse, surfaces villosulous abaxially, strigose to glabrescent adaxially. Peduncles incurved-ascending, 3–10(–12.5) cm. Racemes 10–30-flowered; axis 2.5–10 cm in fruit; bracts 1–3(–4.5) mm; bracteoles 2. Pedicels 1.5–4.3 mm. Flowers 14–17(–18) mm; calyx ovoid-campanulate to subcylindric, gibbous behind pedicel, 9.5–12.3 mm, villosulous or villous-tomentulose, tube 7.6–9.8 mm, lobes triangular, 2.3–3.7 mm; corolla dull yellow; banner strongly recurved or recurved through 90°; keel 12–15 mm. Legumes pendulous (or humistrate, apparently ascending), green or purple-mottled becoming stramineous, incurved through 0.5 spiral, lunately or falcately oblong, narrowly oblong-ellipsoid, or linear-oblong, laterally compressed, bicarinate by sutures, 22–30 × (4–)4.5–8 mm, fleshy becoming woody, villosulous or glabrous; stipe (7–)10–22 mm. Seeds 18–30.
Phenology: Flowering May–Jul.
Habitat: Sagebrush valleys, silty meadows, openings in ponderosa pine forest, on dry sandy or clay substrates mostly of volcanic origin.
Elevation: 1200–1900 m.
Distribution
Calif., Nev.
Discussion
The strongly and abruptly recurved banner, evident even in pressed material, is diagnostic for flowering material of Astragalus gibbsii and distinguishes it from A. curvicarpus, with which it had been once combined. The connate stipules distinguish A. gibbsii from all other species of sect. Collini. It occurs in the eastern Sierra Nevada region.
Selected References
None.