About Astragalus agrestis Douglas ex G.Don
Astragalus agrestis Douglas ex G.Don, commonly known as purple milkvetch, is a perennial herb. It grows a slender but sturdy stem from an underground caudex, and grows either leaning or upright to a maximum height near 30 centimeters. The stem is often roughly hairy. Its alternately arranged leaves grow up to 10 centimeters long, and are made up of several pairs of leaflets, each up to 2 centimeters long. Leaflets are oval to lance-shaped and may have notched tips. The inflorescence is an oval-shaped cluster holding up to 15 pealike flowers, which range in color from purple or pink-tinted to nearly white. Each flower grows up to 2 centimeters long, and blooming occurs from May to August. The fruit is an oval-shaped legume pod up to one centimeter long; it is dark colored with white hairs, and dries to a papery texture. When grown in garden settings, the plant's extensive root network spreads enthusiastically, so it must be confined if the landscaper does not want a large patch of purple milkvetch.
