Oxytropis sericea var. sericea
Plants 14–45 cm. Leaves 6–28 cm; stipules glabrous or densely pilose abaxially; leaflets (9 or)11–19(or 21). Peduncles 7–30 cm, axis 1.5–18 cm in fruit. Racemes 5–20+-flowered. Calyces 9–12 mm, tube 6.5–9 mm, lobes 2.5–4 mm. Corollas white or yellowish, fading whitish or yellowish, or polychrome in populations, 18–27(–28) mm, keel tip maculate. Legumes 15–22 × 5–7 mm. 2n = 24, 48.
Phenology: Flowering spring–early summer(–fall).
Habitat: Plains, prairies, foothills to mountain summits.
Elevation: 600–3100 m.
Distribution
Colo., Idaho, Kans., Mont., Nebr., Nev., N.Mex., Okla., Oreg., S.Dak., Tex., Utah, Wyo.
Discussion
Variety sericea forms hybrids with Oxytropis lambertii where the two entities come in contact, and occasionally where only one parent is known to occur. Especially impressive hybrid populations occur on the high plains and in outliers of the Rocky Mountains where O. sericea and the montane populations of O. lambertii are sympatric or nearly so. The swarms of hybrids, backcrosses, and derivatives at Nederland, Colorado, are especially distinctive, with floral colors and sizes not readily evident in either of the parental types. Such swarms occur widely at least in Colorado and Wyoming.
Selected References
None.