Purple prairie-clover

Dalea purpurea, commonly known as purple prairie clover, is a perennial herb in the family Fabaceae native to central North America, ranging across the Great Plains from Saskatchewan and Manitoba south through the Midwest to Texas and northern Mexico. The plant develops from a deep taproot reaching 1.5 to 2 metres into the soil and produces clumps of erect to ascending wiry stems 30 to 90 centimetres tall, often becoming somewhat woody at the base. The leaves are alternate, pinnately compound with three to seven narrow linear leaflets 1 to 2.5 centimetres long, dotted beneath with small glands and folding inward in dry weather. The inflorescences are dense cylindrical to ovoid terminal spikes 2 to 7 centimetres long bearing many small purple to rose-purple pea-like flowers, opening from the bottom upwards in mid to late summer. The flowers have a five-toothed hairy calyx and conspicuous protruding orange anthers. Fruits are small one- or two-seeded indehiscent pods enclosed in the persistent calyx. It is a key legume of native tallgrass and mixed-grass prairie.