Smallflowered Milkvetch

Hamosa nuttalliana (DC.) Rydb.; Small, Fl. SE. U.S 617, 1332. 1903.
Astragalus micranlhus Nutt. Jour. Acad. Phila. 2: 122. 1821. Not .4. mkranthus Desv. 1814.
Astragalus Nuttallianus DC. Prodr. 2: 289. 1825.
Tragacantha micrantha Kuntze, Rev. Gen. 941. 1891.
Astragalus Nutlallianus enneajugus M. E. Jones. Contr. W. Bot. 8: 22. 1898.
Astragalus Nutlallianus quadrilateralis M. E. Jones, Contr. W. Bot. 8: 22. 1898.
An annual; stem erect or ascending, 1-5 dm, high, branched at the base, sparingly strigulose or glabrate, striate; leaves ascending, 5-7 cm. long; stipules lanceolate, acuminate, 4-6 mm. long; leaflets cuneate to elliptic, 5-15 mm. long, 2-6 mm. wide, usually emarginate at the apex, cuneate at the base, glabrous above, sparingly strigulose on the veins and margins beneath; peduncles 4-8 mm. long; racemes very short, 3-10-flowered; bracts subulate, 3-4 mm. long; calyx sparingly strigose, the tube 4 mm. long, the teeth subulate, distinctly longer; corolla purple-tipped; banner obovate, retuse, 5-6 mm. long; wings slightly shorter, the blade obliquely oblanceolate, obtuse, with a reflexed auricle; keel-petals shorter, the blade broadly lunate, acutish, with a reflexed auricle; pod linear, 2-3.5 cm. long, 3 mm. wide and thick, glabrous, arcuate below the middle, sulcate on the lower suture, cordate in cross-section.
Type locality: Red River, Arkansas.
Distribution: Texas, Oklahoma, and western Arkansas; also at Palisades, Delta County, Colorado.

Annual, Her bs, Taproot present, Nodules present, 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 free, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 10-many, Leaves hairy on one or both surfaces, 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 pinkish to rose, Petals blue, lavander to purple, or violet, Banner petal narrow or oblanceolate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurre d, 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 tardily or weakly dehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruit strongly curved, falcate, bent, or lunate, Fruit rugose wrinkled or reticulate, Fruit exserted from calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit 11-many seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus nuttallianus is a species of milkvetch known by the common names smallflower milkvetch and turkeypeas. It is native to the southwestern and south central United States and northern Mexico, where it can be found in many types of habitat, often in dry areas.

This is an annual herb which is variable in appearance, especially across varieties. It produces slender, hairy stems which reach 4 to 45 centimeters in length. The leaves are up to 6.5 centimeters long and are made up of several oval-shaped pointed or round-tipped leaflets. The inflorescence bears 1 to 4 white to purple or bicolored flowers, each less than a centimeter in length. The fruit is a legume pod 12 to 26 mm long.

There are several varieties of this species:

A. n. var. austrinus - distributed from California to Oklahoma to northwestern Mexico A. n. var. cedrosensis - native to the Sonoran Desert A. n. var. imperfectus - native to the southwestern United States A. n. var. macilentus - native to New Mexico and Texas A. n. var. micranthiformis - found in the southwestern United States A. n. var. nuttallianus - known from the central US from Kansas to Louisiana A. n. var. trichocarpus - native to Texas and Oklahoma A. n. var. zapatanus - Texas endemic