Calopogonium mucunoides aka Calopo

Calopogonium mucunoides is a legume in the Fabaceae family. Its common names include calopo and wild ground nut. It comes from Mexico, tropical America, and the West Indies. It grows in thickets, rocky ground, and open woodland. Some wild sites are moist, while others are dry. People have introduced it across much of the humid tropics. It has become naturalized in Indonesia and Malaysia.

This fast-growing herb can live as an annual or short-lived perennial. Its stems creep, trail, or twine around nearby supports. Climbers can reach about 16 feet [5 metres]. Trailing growth forms tangled cover about 1–1.6 feet [0.3–0.5 metres] deep. Stems can form roots where they touch moist soil. This helps the plant spread across the ground. Insects pollinate its flowers, and plants are self-fertile. Flowers give rise to seedpods. The supplied sources give no flowering season or detailed leaf description.

Calopo grows best in hot, humid conditions with full sun. Shade cuts its growth sharply, and frost can kill it. PFAF places it in USDA zones 10–12. It prefers daily temperatures of 24–32°C. Its best growth occurs where yearly rainfall exceeds 1,250 millimetres. It tolerates some drought, but long dry seasons may kill it. Keep the soil moist, with good drainage. It grows in sand, loam, and clay, but prefers clay. It also thrives in strongly acid soil, around pH 4.5–5.

Growers use calopo as ground cover, fodder, and green manure. It fixes nitrogen and helps improve soil fertility. Its cover shields the soil and helps keep it cool. Fallen leaves form mulch that can suppress many weeds. Plantations use it beneath crops such as rubber and oil palm. It also helps hold soil in place. These uses make it more useful as a working cover crop than an ornamental. Its fast spread also gives it weed potential.

Seed is the main way to raise new plants. Fresh seed often has a hard coat that slows germination. Seed treatments can help overcome this barrier. Stems root on the ground, but planted cuttings establish poorly. The sources name no particular pests or diseases. They report no known hazards, but this does not prove safety. They list no known human food or medicinal uses.