Thickpod Milkvetch

Brachyphragma pachypus (Greene) Rydberg
Astragalus pachypus Greene, Bull. Calif. Acad. 1: 157. 1885.
A perennial; stem stout, 5-12 dm. high, cinerous-strigulose, flexuose, terete; leaves spreading, S-12 cm. long; stipules broadly deltoid, 3 mm. long; leaflets 13-17, linear, 1-2 cm. long, 2-3 mm. wide, canescent-strigose on both sides, obtuse; peduncles 1-2 dm. long, strict; racemes 3-10 cm. long, in fruit lax; bracts lanceolate, 3 mm. long; calyx strigose with mixed white and black hairs, the tube 4 mm. long and about as broad, the teeth subulate, 3 mm. long; corolla white or cream-colored, about 15 mm. long; banner broadly obovate, notched, strongly arcuate; wings about 12 mm. long, the blade obliquely oblanceolate, with a large basal auricle; keelpetals fully 1 cm. long, the blade broadly lunate, strongly arcuate, obtuse; pod stipitate, the stipe stout, about 7 mm. long, the body about 2 cm. long, 5 mm. wide and about as thick, falcate, at first fleshy, in age coriaceous, nearly 2-celled, the septum almost reaching the upper suture.
Type locality: Mountains. Kern County. California.
Distribution: California, from Kern County south.

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, Leaves compound, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, 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 hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, Petals pinkish to rose, 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 stipitate, Fruit freely dehiscent, Fruit oblong or ellipsoidal, Fruit rugose wrinkled or reticulate, Fruit or valves persistent on stem, Fruit fleshy, Fruit coriaceous or becoming woody, 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 pachypus is a species of milkvetch known by the common name thickpod milkvetch. It is endemic to California, where it is known from many types of open habitat across the southern half of the state. This is a robust perennial herb forming stands of tough, wiry stems up to 80 centimeters tall. Leaves are up to about 16 centimeters long and are made up of many narrow leaflets. The plant flowers in inflorescences of 4 to 28 cream-colored flowers. The fruit is a sharp-beaked legume pod up to about 3 centimeters long which dries to a leathery, mostly hairless texture. There are two varieties of this species. The rarer, Jaeger's bush milkvetch (var. jaegeri), is known mostly from western Riverside County.