Dwarf White Milkvetch

Hesperastragalus catalinensis (Nutt.) Rydb. bull. Torrey Club 53: 169. 1926.
Astragalus catalinensis Nutt. Proc. Acad. Phila. 4: 9. 1848.
An annual; stem branched at the base, 1-3 dm. high, sparingly strigulose; leaves 3-5 cm. long, ascending; stipules deltoid, 2-4 mm. long; leaflets 11-17, narrowly linear, 4-12 mm. long, deeply notched into 2 acute teeth at the apex, glabrous above, pilose or strigose beneath; peduncles 3-5 cm. long; racemes dense, oblong, 1-1.5 cm. long; bracts lanceolate, 1-2 mm. long; calyx black -hairy, the tube 1.5-2 mm. long, the teeth subulate, 1-1.5 mm. long; corolla 5-7 mm. long, purple or white; petals similar to those of //. didymocarpus; pod nearly globose, nearly 3 mm. long, pubescent with comparatively short crisp hairs; seeds mostly solitary in each cavity.
Type locality: Island of Catalina, California. Distribution: Southern California and Lower California.

Annual, Herbs, Ta proot present, Nodules present, Stems very short, acaulescent or subacaulescent, 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 5-9, Leaflets 10-many, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence axillary, Bracts very small, absent or caducous, 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, Banner petal narrow or oblanceolate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Keel t ips 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 indehiscent, Fruit oblong or ellipsoidal, Fruit enclosed in calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit hairy, Fruit 2-seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus didymocarpus is a species of milkvetch known by the common names Dwarf white milkvetch and Two-seeded milkvetch. It is native to the southwestern United States and northern Mexico, where it can be found in many types of habitat.