Centrosema virginianum (Butterfly Pea)

Native to the Americas, from the eastern United States through tropical regions, this herbaceous perennial vine climbs by twining its stems or trails along the ground. Its leaves have three leaflets. Violet flowers with pale centers are upside down compared with many pea flowers, with the broad banner petal facing downward. Each flower lasts about half a day, while new flowers open through the flowering season. Bees pollinate the flowers, and the foliage feeds northern cloudywing and long-tailed skipper caterpillars. Root nodules fix nitrogen, and its extensive roots help stabilize sandy soil. Photographed in Colombia.