Hartweg's Milkvetch

Hamosa hartwegii (Benth.) Rydb. Bull. Torrey Club 54:333. 1927.
Astragalus Harlwegii Benth. PI. Hartw. 10. 1839. Tragacanlha Harlwegii Kuntze, Rev. Gen. 945. 1891.
A perennial; stem 3-6 dm. high, sparingly strigose, striate, flexuose; leaves spreading, 6-8 cm. long, acuminate; leaflets 15-21, oblong or oblanceolate to nearly linear, 6-15 mm. long, acute at the base, obtuse at the apex, glabrate above, strigose beneath ; peduncles 5-10 cm. long; racemes 4—8 cm. long, rather dense; bracts lanceolate, 2 mm. long; flowers nearly sessile, reflexed; calyx white-strigose, the tube 2 mm. long, the teeth deltoid, less than 1 mm. long; corolla white or ochroleucous, 5-7 mm. long; banner broadly obovate, strongly arched at the middle; wings as long, the blade broadly obovate; keel-petals shorter, the blade semiorbicular; pod obliquely lance-oblong, slightly arcuate, 12-15 mm. long, 3 mm. wide and as thick, white-strigulose, the cross-section inversely V-shaped.
Type locality: Aguascalientes. Distribution: Coahuila to Sonora and Mexico.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems erect or ascending, 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 free, Stipules clasping stem at the base, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 10-many, Leaves hairy on one or both surfaces, Inflorescences spikes or spike-like, Inflorescence axillary, Bracts very small, absent or caducous, Flowers zygomorphic, Calyx 5-lobed, Calyx gibbous, inflated, or spurred, Calyx glabrous, Petals separate, Corolla papilionaceous, Petals clawed, Petals blue, lavander to purple, or violet, Banner petal narrow or oblanceolate, Wing petals narrow, ob lanceolate 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 freely dehiscent, Fruit tardily or weakly dehiscent, Fruit oblong or ellipsoidal, Fruit fleshy, Fruit coriaceous or becoming woody, Fruit exserted from calyx, 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.