Though the flowers are small and the foliage scanty, the shaded effect of mingled yellow and orange of these plants is rather pretty, as we see them by the wayside, The many, long, smooth, reed-like stems grow from two to five feet high, branching from the root, somewhat woody below, loosely spreading, or sometimes half lying on the ground. The leaves are almost smooth, very small and far apart, with from three to six, oblong leaflets, and the flowers, from a quarter to half an inch long, are clustered in close little bunches along the stem, forming long wands, tipped with green buds, and shading downward through the bright yellsw of the larger buds to the orange of the open flowers and the dull red of the faded ones. The pod is incurved, tipped with the long style. This is common and widely distributed, a perennial, but said to live only two or three years. In the south it often makes symmetrical little bushes, pleasing in appearance. It is a valuable bee-plant. A. Wrightii of Arizona, Utah, New Mexico, and Colorado, is quite leafy, with erect stems and branches, bushy and woody at base, the small leaflets from three to five in number. The flowers, without pedicles, are much like the last, but over half an inch long, yellow becoming reddish, with a blunt keel, and scattered all over the plant.
There are several kinds of Thermopsis, of North America and Asia; stout, perennial herbs, with woody rootstocks; leaflets three; stipules conspicuous, leaf-like; flowers large, yellow, with short, bracted flower-stalks; calyx bell-shaped, five-cleft; standard broad, in the western species, shorter than the oblong wings, keel nearly straight, blunt, the same length as the wings; stamens ten, separate, curving in; style slightly curving in, stigma small; pod flat, long or oblong, straight or curved, with a very short" stalk and several seeds. Thermopsis, sometimes called False Lupine, is distinguished from Lupinus by its stamens, which are separate, instead of united into a sheath. The Greek name means "lupine-like."