Prairie Thermopsis

Perennial, Herbs, Plants with rhizomes or suckers, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs glabrous or sparsely glabrate, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules persistent, Stipules free, Leaves compound, Leaves palm ately 2-3 foliate, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 3, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence terminal, Bracts conspicuously present, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals orange or yellow, Banner petal suborbicular, broadly rounded, Wing petals narrow, oblanceolate to oblong, Wing petals auriculate, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens completely free, separate, Filaments glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit strongly curved, falcate, bent, or lunate, Fruit exserted from calyx, Fruit compressed between seeds, Fruit glabrous or glabrate, Fruit hairy, Fruit 3-10 seeded, Seeds ovoid to rounded in outline, Seed surface smoo th, Seeds olive, brown, or black.

Thermopsis rhombifolia, also known as prairie thermopsis, is a flowering plant in the legume family. It is native to North America, where it is found in the Great Plains, with extensions into the lower canyons of the Rocky Mountains. Its natural habitat is dry grasslands and woodlands.

It is a perennial herb that produces yellow flowers in the spring.