Description:
Railroad vine is a trailing species whose runners may reach over 30 feet in length.  Runners are succulent and have a milky colored sap. Leaves are 2-lobed, alternate, and elliptical in shape, measuring 2 - 5 inches in length with short petioles.  Taproots are long and deep, sometimes penetrating more than a meter into the sand.  Flowers are axillary, 1.5 – 5.5 inches in diameter, and either angular or flattened. Corollas are funnel-shaped.  Color ranges from pink to red-purple or violet, usually darker at the inside base of each flower.

Habitat:
Railroad vine is a rapid colonizer of sand dunes and scrub areas where its deep roots help stabilize sands to prevent erosion.  It is common on beaches, dunes, and scrub.  It has also naturalized into upland areas and along roadsides, presumably from its seeds being dispersed by winds or animals. 

Similar Species:
Railroad vine can be mistaken for the bay bean, Canavalia rosea.  However, the leaves, and flowers of the bay bean are significantly smaller.  Bay bean also has shorter vines, has compound leaves with 3 leaflets, and has fruiting pods 4-5 inches in length.  Conversely, railroad vine has branches that may grow over 30 feet in length, 2-lobed leaves, and pods less than 0.5 inches in length. 

Range:
Railroad vine is one of the most widely distributed beach plants throughout tropical and subtropical areas in the world, its range extending from approximately 30° North latitude to 30° South latitude. It occurs throughout tropical North and South America, east central Africa, west central Africa, India, Asia, and Australia.