Macroptilium lathyroides has spread throughout Florida and has become increasingly abundant in the Florida Keys, particularly along the U.S. 1 corridor. However, M. lathyroides has also been observed forming dense monocultures in tidal marsh, beach dune, coastal berm and ruderal areas in the Florida Keys.
Macroptilium lathyroides is native to tropical America and is a member of the Fabaceae family. Plants form dense monocultures and grow erect to a height of approximately 0.5 meters. The leaves are compound with three leaflets per leaf, and red to purple flowers develop on long stalks. The flower petals are uneven with the wing petals being larger than the lower petals. Fruits develop as paired long pods that split open when mature; they contain numerous wind-dispersed seeds.