Astragalus vexilliflexus Sheldon

Homalobus amphidoxus (Blankinship) Rydberg
?Aslragalus miser A. Gray, Proc. Am. Acad. 6: 228. 1864. Not A . miser Dougl. 1831. Astragalus amphidoxus Blankinship, Mont. Agr. Coll. Stud. 1: 72. 1905. Homalobus miser Rydb. Bull Torrey Club 40: 52, in part. 1913.
A cespitose perennial, with a thick woody root; stems numerous, 1-1.5 dm. high, sparsely strigose; leaves ascending, 5-8 cm. long; stipules strigose, deltoid, 3-4 mm. long; leaflets 13-17, lanceolate to lance-linear, acute, glabrous above, strigulose beneath, 1-1.5 cm. long, 2-4 mm. wide; peduncles 4-6 cm. long; racemes 2-3 cm. long, 6-8-flowered; bracts lanceolate, 2 mm. long; pedicels 1 mm. long; calyx strigose with black hairs, the tube 2 mm. long, the teeth subulate, 1.5-2 mm. long; corolla violet-purple, S mm. long; banner obovate, notched at the apex; wings shorter, the blade obliquely obovate, with a rounded auricle; keel-petals much shorter, similar but broader, rounded at the apex; pod obliquely oval, 7-8 mm. long, 2.5 mm. wide, strigose, the upper suture nearly straight.
Type LOCALITY: Sky High, Unionville, Montana. Distribution: Montana to Washington.

Homalobus vexilliflexus (Sheldon) Rydb. Mem. N. Y Bot. Gard. 1: 249. 1900.
Astragalus pauciflorus Hook. Fl. Bor. Am. 1: 149. 1831. Not .4. pauciflorus Pall. 1800. Tragacantha pauciflora Kuntze, Rev. Gen. 947. 1891. Astragalus vexilliflexus Sheldon, Minn. Bot. Stud. 1: 21. 1894.
A perennial, with a cespitose caudex; stems many, ascending, or decumbent, 1-2 dm. high, strigose; leaves 2-5 cm. long; upper stipules lanceolate, green, 2-3 mm. long, strigose, the lower deltoid, connate, more or less purplish; leaflets 7-11, oblong, acute, 6-15 mm. long, 2-4 mm. wide, strigose beneath, slightly so or glabrate above; peduncles 2-3 cm. long; racemes short, 2-5-flowered ; bracts lanceolate, 2 mm. long; calyx strigose, the tube 2 mm. long, the teeth subulate, 1 mm. long; corolla purple; banner obovate, 6-7 mm. long, retuse; wings 5 mm. long, the blades obliquely oblanceolate, falcate, the claw short; keel-petals strongly lunate, ochroleucous, with purple rounded tip; pod elliptic, 8-10 mm. long, 3 mm. wide, acute at each end, sessile, strigose; seed almost black, rounded-reniform, 2.5 mm. long, nearly 2 mm. broad.
Type locality: Rocky Mountains, Canada.
Distribution: Saskatchewan to British Columbia and Wyoming.

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 or branches arching, spreading or decumbent, Stems prostrate, trailing, or mat forming, 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, Inflorescence axillary, Bracts very small, absent or caducou s, Flowers zygomorphic, Calyx 5-lobed, Calyx glabrous, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Petals pinkish to rose, 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 unilocular, Fruit tardily or weakly dehiscent, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit 3-10 seeded, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus vexilliflexus adalah spesies tumbuhan yang tergolong ke dalam famili Fabaceae. Spesies ini juga merupakan bagian dari ordo Fabales. Spesies Astragalus vexilliflexus sendiri merupakan bagian dari genus Astragalus. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh E.Sheld..

Astragalus vexilliflexus là một loài thực vật có hoa trong họ Đậu. Loài này được E.Sheld. miêu tả khoa học đầu tiên.