Great Bladdery Milkvetch

Phaca megacarpa Nutt.; T. & G. Fl. N. Am. 1: 343. 1838
Astragalus megacarpus A. Gray, Proc. Am. Acad. 6: 215. 1864. Astragalus megacarpus Parryi A. Gray, Bot. Calif. 1: 148. 1876. Tragacanlha megacarpa Kuntze, Rev. Gen. 946. 1891. Astragalus megacarpus prodigus Sheldon, Minn. Bot. Stud. 1: 136. 1894.
Perennial, with a cespitose caudex; stems mostly 1-7 cm. high, covered by numerous scalelike, persistent stipules; leaves 7-12 cm. long, ascending; stipules scaiious, deltoid, 5 mm. long; leaflets 7-21, broadly oval or obovate, 1-2 cm. long, 5-15 mm. wide, often retuse, glabrous and somewhat glaucous; peduncles 2-5 cm. long; racemes 3-S-flowered; calyx-tube campanulate, 9-10 mm. long, the lobes lance-subulate, 5-6 mm. long; corolla ochroleucous, nearly 2 cm. long; banner oblanceolate, gradually tapering below; wings shorter, the blade oblong-lunate, obtuse, only slightly falcate, shorter than the claw; keel-petals about 15 mm. long, the blade broader, rounded at the apex, a little more than half as long as the claw; pod glabrous, the stipe 3-5 mm. long, the body ellipsoid, 4-6 cm. long, 2-2.5 cm. wide; seeds obliquely reniform.
Type locality: Plains of the Rocky Mountains [Wyoming]. Distribution: Wyoming to southwestern Utah.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems very short, acaulescent or subacaulescent, 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 membranous or chartaceous, Stipules persistent, Stipules free, Stipules clasping stem at the base, 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, Inflorescence axillary, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Petals pinkish to rose, 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, Filam ents glabrous, Style terete, Style persistent in fruit, Fruit a legume, Fruit stipitate, Fruit unilocular, 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.