Thermopsis montana var. montana

Herbs 2–7 dm, appressed-pubescent to thinly villous. Stems stiffly erect, solitary or clustered, few-branched, from woody rootstock or rhizomes; branches moderately zigzag. Leaves: petiole 1–2.5 cm; leaflet blades elliptic, narrowly elliptic, or obovate, 3.5–8 × 0.7–2.5 cm, not conspicuously net-veined abaxially, surfaces appressed-pubescent. Racemes 4–18 cm; bracts elliptic to widely ovate. Flowers 1.6–2 cm. Legumes villosulous. 2n = 18.

Phenology: Flowering May–Jun.
Habitat: Open moist margins of creeks and lakes, swales, meadows, pine woodland, sagebrush or pinyon.
Elevation: 2000–3200 m.

Distribution

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Ariz., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.

Discussion

Variety montana is widespread and highly variable; it can usually be distinguished from var. ovata by its smaller habit, narrower leaflets and bracts, and greater tendency to spread by rhizomes. In southwestern Oregon, the two varieties appear to intergrade.

Selected References

None.

Lower Taxa

None.