Widow's milkvetch, Layne milkvetch
The Mojave Desert (AZ, CA, NV)
Washes, sandy plains, disturbed areas; 1,500 to 5,000 feet
Up to 6 inches long; divided into 11 to 23 round or ovate leaflets
Astragalus layneae is one of the most abundant milkvetch species of the Mojave Desert. Stems are erect or ascending, and, like the leaves, have a sparse covering of coarse, light grey hairs. The compound leaves have a terminal leaflet and 5 to 11 pairs of lateral leaflets, all similar in size and shape, and around half an inch in length. Leaflets are not overlapping, and are generally held at an angle, above the plane.
Flowers form in a vertical cluster with up to 45 heads; initially compact but elongating as it matures so that the flowers become quite well separated. Flowers point upwards at first, later horizontally outwards. Calyces are light-colored, yellow to reddish, covered with short, appressed hairs that are black (mostly) and white. Petals are colored white to pale pink, but purple along the edges (banner) and at the tip (keel, wings). The banner petal is curved backwards at around 50 degrees. Buds are creamy yellow. Fruits are greenish red, strongly curved, not inflated, and have a covering of white, wavy hairs.