Macroptilium lathyroides

Native to tropical and subtropical America, this plant is an annual or short-lived perennial herb with erect, trailing or twining stems. Its red to reddish-purple flowers have a spirally twisted keel. The long, slender pods split forcefully as they ripen, twisting their valves and scattering the seeds. The plant is grown as livestock forage and used as a green manure or cover crop because of its nitrogen fixation. It has become naturalized widely and is regarded as an environmental weed in Queensland and the Northern Territory of Australia. Photographed in the department of Atlantico, Colombia.