Showy partridge pea is an annual with upright stems, usually without branches. Flowers 1 to several, about 1 inch across, arising from leaf axils. Petals 5, yellow (rarely white), sometimes reddish-tinged at the base; one side petal curves around the stamens; the lowest petal is the largest. Blooms July–October. Leaves compound, pinnately divided, with up to 18 leaflets that are narrow, short, linear. Leaflets fold up along the midrib at night into a sleeping position, and often upon being touched. Fruit a legume (short beanlike pod) 1–2½ inches long, black when mature. When mature and dry, the two sides separate suddenly, flinging the seeds a yard or more away.
Similar species: Small-flowered, or sensitive partridge pea (C. nictitans) is about half as tall, branches a bit more, and has inconspicuous flowers no bigger than about ½ inch wide. It grows mostly south of the Missouri River.