Milkvetches usually have several flowers (rarely single) in stalked clusters from leaf axils, generally showy, white or yellowish to reddish or purple. The banner of the corolla is usually well bent up from the wings, the wings are mostly longer than the blunt or rounded to slightly pointed keel. The fruits are pods, rounded or linear, straight to coiled, membranous or fleshy and with a woody or bony texture when dried, often conspicuously inflated, compressed either height- or side-wise, with one or both seams often intruded to form a partial to complete lengthwise wall which divides the pod into 2 compartments. The genus are annual to perennial herbs with odd-pinnate leaves in pairs, with one leaflet at the end, the leaflets usually jointed to the leaf axis. The stipules in pairs at the leaf stalk bases are free or joined to each other opposite the leaf stalks. petioles. The plants have various types of hairs, but they are usually flat-lying, mostly simple but sometimes attached near the middle or closer to one end, and thus 2-branched, referred to as dolabriform or T-shaped hairs.

The flowering plant genus Astragalus, the common name "milkvetch", containing upwards of 2500, mostly perennial species, are distributed primarily around the northern hemisphere and South America. Astragalus species are found mostly in cool temperate semi-arid and arid continental regions of the world. Many species are narrow endemics, often found in marginal habitats, while relatively few are widespread. Astragalus is especially diverse in southwest Asia, the Sino-Himalayan region, western North America, where we have about 400-450 species, and along the Andes in South America. Astragalus is also diverse in Mediterranean climatic regions, along the Pacific coasts of North and South America, and in southern Europe and northern Africa.

The recorded history of Astragalus dates back at least to the 1st century A.D., and the genus was well known to western European botanists of the 17th century. A number of species of Astragalus from southwest and southcentral Asia (e.g., A. gummifer, Iran) are the source of "gum tragacanth" - a substance tapped from roots or stems with hydrophilic and colloidal properties valuable in ice creams, lotions, pharmaceuticals, used since the time of ancient Greece. A few species are edible (A. canadensis, N. America) or have medicinal uses, and some are used for livestock forage (A. cicer, USA), but a large number of North American species are poisonous (e.g., A. mollissimus, N. America), especially to livestock and wildlife, a property due to the accumulation of selenium from soils or synthesis of toxic levels of certain nitrotoxins and alkaloids in the foliage - hence the name "locoweed" ("loco" is Spanish for crazy) given to many species of the Astragalus genus.