Thermopsis rhombifolia (Nutt. ex Pursh) Nutt. ex Richardson
prairie golden bean (prairie thermopsis)
Fabaceae (Pea family)

Introduction to Vascular Plants


© Jim Riley     (Photo ID #12724)


E-Flora BC Static Map

Distribution of Thermopsis rhombifolia
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Species Information

Perennial herb from a thick woody rhizome; stems erect to ascending, 10-40 cm tall, mostly unbranched, appressed-hairy to nearly glabrous.
Alternate, palmately compound, stalked; leaflets 3, oblanceolate to elliptic, 1.5-3 cm long, short-hairy on both surfaces or glabrous above; lowest stipules papery, sheathing, the upper ones large, egg-shaped, resembling leaflets, joined to the leaf-stalk at the base.
Inflorescence a dense, stalked, erect, terminal raceme, 5-10 cm long, of 10 to 30 erect, pea-like flowers; corollas bright yellow, 17-25 mm long; calyces bell-shaped, 8-13 mm long, 2-lipped, the upper lip 2-toothed, the lower 3-toothed, the teeth triangular.
Pods, linear, flattened, 4-8 cm long, spreading and curved, stiff-papery, usually soft-hairy; seeds several.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Habitat and Range

Mesic to moist meadows and grasslands in the montane zone; rare in SE BC, E to MB and S to NE, ND, CO, ID and CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Thermopsis arenosa A. Nels.
Thermopsis montana var. ovata (B.L. Rob. ex Piper) H. St. John
Thermopsis ovata B.L. Rob. ex Piper
Thermopsis rhombifolia var. annulocarpa (A. Nels.) L.O. Williams
Thermopsis rhombifolia var. arenosa (A. Nels.) Larisey
Thermopsis rhombifolia var. ovata (B.L. Rob. ex Piper) Isely
Thermopsis rhombifolia var. rhombifolia