Chamaecrista fasciculata aka Partridge Pea

Chamaecrista fasciculata, or partridge pea, is an annual wildflower. It belongs to the legume family, Fabaceae. Its native range spans southeastern Canada and central and eastern America. It grows in open woods, prairies, grasslands, and disturbed ground. Wild plants also grow on rocky slopes, ridges, and bluffs. Many sites have sandy soil and little shade.

Garden plants reach 1–3 feet (0.3–0.91 metres) tall. They can spread to about 3 feet (0.91 metres). Short plants stand upright, while taller ones may sprawl. The green leaves have a fine, feathery look. Each pinnate leaf has up to 20 narrow leaflets. Leaves grow in an alternate pattern along the stems. They fold when touched and close as night falls. Glands on the leaf stalks draw insects.

Yellow flowers appear from June to September. Chicago records flowering from July into October. Groups of two to six flowers grow at leaf joints. Each flower measures about an inch across. Five rounded petals differ in size, giving an uneven outline. Red-purple marks lie near the petal bases, beside red stamens. Flat, narrow pods follow the flowers. They reach about two and a half inches long. Green pods turn brown, then split to scatter seeds. This seed release runs from July into November.

Grow this plant in full sun with good soil drainage. It also tolerates some light shade. It accepts sand, loam, and clay, in acid or neutral soil. Moist soil suits it, but established plants tolerate drought. Poor soil can help by limiting competition from other plants. Sources place it in USDA zones 3–9. It grows with little care and starts well from seed. Sow seeds from late March through May. It reseeds freely and can spread strongly across dry, open ground.

Partridge pea suits meadows, native gardens, and areas left to naturalize. Its roots help hold soil on banks and slopes. As a legume, it fixes nitrogen and improves soil fertility. Bees and butterflies visit its flowers. Cloudless sulphur, little yellow, and sleepy orange caterpillars use it as a host. Songbirds, quail, and wild turkeys eat the seeds. The plants also give game birds cover. Serious pest and disease problems are uncommon. Leaf spot and mildew can occur, and deer browse the leaves. No edible or medicinal uses are known in the supplied evidence. Plants For A Future reports toxicity to grazing animals.