Prairie-clovers are herb-like perennials, glandular-dotted with small pits, with small, pinnately divided leaves with single end leaflet and small, linear, bristle-like stipules. The flowers are numerous, arranged in dense, terminal and axil-borne, bracted spikes, with color white, pink, or red. The calyx is bell-shaped to trumpet-shaped, usually prominently nerved, the 5 teeth lanceolate, about equal. The corolla is irregular but not truly pea-like, consisting of apparently of 5 petals, one of them (probably the only true petal) larger, broader and with a narrowed petal stalk, and joined at base to the calyx. The other 4 petals (due to their position almost surely sterile stamens) are narrow-stalked, joined to the short staminal tube and alternate with the 5 fertile stamens. The pod is 1- or 2-seeded, staying closed, usually contained in the calyx. The genus has about 36 species of N. America, especially common in the plains states and southeastward. The name comes from the Greek Petalon, petal, and stennon, stamen, in reference either to the union of the petals and stamens or to the presence of petal-like stamens.
Guide to Identify Presented Species of Genus Dalea
D. purpurea Purple Prairie-clover Plant erect, 30-60 cm tall. Dry plains and foothills.
Flowers purple, in narrow, dense spikes, 2-7 cm tall and about 1.5 cm thick.
Leaves odd-pinnate, the 3-7 leaflets linear, 10-20 mm long and 1-2 mm broad.