Troubled Milkvetch

Perennial, Herbs, Stems woody below, or from woody crown or caude x, Taproot present, Nodules present, Stems very short, acaulescent or subacaulescent, Stems or branches arching, spreading or decumbent, 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, 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, Inflorescences globose heads, capitate or subcapitate, 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, Petals bicolored or with r ed, 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 abruptly curved, or spirally coiled, 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 elongate, straight, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit beaked, Fruit glabrous or glabrate, Fruit hairy, Fruit 2-seeded, Fruit 3-10 seeded, Seeds cordiform, mit-shaped, notched at one end, Seed surface smooth, Seeds olive, brown, or black.

Astragalus anxius is a rare species of milkvetch known by the common names troubled milkvetch and Ash Valley milkvetch. It is endemic to northern Lassen County, California, where it is critically imperiled. It was formally described in 1992.