Broadkeel Milkvetch

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems very short, acaulescent or subacaulescent, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules membranous or chartaceous, Stipules persistent, Stipules connate to each other, forming a tuber or sheath, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 5-9, Leaflets 10-many, Leaves hairy on one or both surfaces, Flowers in axillary clusters or few-floweredracemes, 2-6 flowers, Inflorescences racemes, Inflorescences globose heads, capitate or subcapitate, Inflorescence axillary, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Petals ochroleucous, cream colored, Petals blue, lavander to purple, or violet, Petals bicolored or with red, purple or yellow streaks or spots, Banner petal narrow or oblanceolate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit humistrate, lying on the ground, Fruit tardily or weakly dehiscent, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit inflated or turgid, Fruit beaked, Fruit glabrous or glabrate, Fruit hairy, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus platytropis is a species of milkvetch known by the common name broadkeel milkvetch. It is native to the western United States from Montana to California, where it lives at high elevation in alpine and subalpine plant communities. This is a small perennial milkvetch which forms a small patch of short silvery-green stems on rocky ground. The leaves may be up to 9 cm (3.5 in) long and are made up of several hairy leaflets. The inflorescence is a head of four to nine pale purple flowers, each just under 1 cm (0.39 in) long. The fruit is a bladdery legume pod which can exceed 3 cm (1.2 in) long.