Silverleaf Indian Breadroot

Psoralidium argophyllum (Pursh) Rydberg
Psoralea argophylla Pursh, Fl. Am. Sept. 475. 1814.
Psoralea incana Nutt. (Fraser, Cat.; hyponym. 1813) Gen. 2: 102. 1818.
Psoralea argophylla decumbens A. Gray. Pacif. R. R. Rep. 12 ! : 41. 1860.
Lotodes argophyllum Kuntze, Rev. Gen. 194. 1891.
Psoralea argophylla robustior Bates, Am. Bot. 20: 16. 1914. A perennial, with a rootstock; stem erect, 3-5 dm. high, silvery -canescent. divaricately branched; leaves digitately 3-5-foliolate; stipules 5-10 mm. long, lanceolate; petioles 2-5 cm. long; leaflets 1.5-4 cm. long, 5-20 mm. broad, elliptic to broadly obovate, obtuse, often mucronate, more or less silky on both sides, usually silvery-white beneath; peduncles 3-8 cm. long; spikes interrupted, 2-4 cm. long; bracts ovate-lanceolate, 5-10 mm. long, longacuminate; flowers 2-4 at each node; calyx densely white-silky; tube about 2 mm. long, campanulate; upper four lobes lanceolate, acute, about 3 mm. long, the lowest lobe lanceolate, long-acuminate, 6-7 mm. or in fruit more than 1 cm. long; corolla dark-blue or purple, 8-9 mm. long; banner broadly obovate; pod ovoid, densely silky, 7-8 mm. long, with a flat straight beak; seed brown, oval, compressed, 4 mm. long.
Type locality: Banks of the Missouri [Dakota].
Distribution: Wisconsin to Saskatchewan, Wyoming, New Mexico, and Missouri.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Plants with rhizomes or suckers, Taproot present, Nodules present, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Stems silvery, canescent, tomentose, cobwebby, or wooly, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules setiform, subulate or aci cular, Stipules persistent, Stipules free, Leaves compound, Leaves palmately 2-3 foliate, Leaves pinnately 3-foliolate, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 3, Leaflets 5-9, Leaves glandular punctate or gland-dotted, Leaves hairy on one or both surfaces, Flowers in axillary clusters or few-floweredracemes, 2-6 flowers, Inflorescences racemes, Inflorescence axillary, Bracts conspicuously present, Bracts hairy, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals blue, lavander to purple, or violet, Banner petal ovoid or obovate, Banner petal auriculate, Wing petals narrow, oblanceolate to oblong, Wing petals auriculate, Wing tips obtuse or rounded, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style hairy, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit oblong or ellipsoidal, Fru it exserted from calyx, Fruit beaked, Fruit hairy, Fruit 1-seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.

Pediomelum argophyllum, synonym Psoralea argophylla, (common name silverleaf Indian breadroot) is a species of legume in the family Fabaceae. The species is native to the central United States, as well as the three Canadian prairie provinces, Alberta, Saskatchewan, and Manitoba. Pediomelum argophyllum grows naturally as a forb, and it grows perennially.