Chamaecrista nictitans is the smaller, less conspicuous cousin of Common Partridge Pea, native across the eastern United States and extending through Mexico into Central and South America. It colonizes woodland borders, roadsides, sandy banks, and wet shores with the opportunistic energy of a plant that asks very little in terms of soil quality or fertility. Like all legumes it builds nitrogen in the soil as it grows, which is why it is used along highways for both pollinator habitat and soil improvement. The thigmonastic response that gives it its common name, leaflets folding shut when touched, is one of those small garden pleasures that never quite becomes ordinary.

The flowers are small yellow blooms that appear in summer and continue into fall, modest compared to those of its relative but produced in enough quantity to attract a useful range of pollinators. The nectar glands on the stem attract wasps, ants, and spiders in addition to bees. Seeds are eaten by birds and small mammals. Growing from 4 to 20 inches tall from a long taproot that anchors it on slopes and banks, it is well suited to erosion control in areas too dry or thin-soiled for more demanding plants. It self-seeds into adjacent disturbed ground readily, which counts as a virtue in a naturalization context and requires management elsewhere.