Habit: Macroptilium lathyroides is an annual that grows prostrate or climbing over other vegetation, is up to 1 m in height with stems covered in short soft hairs. The leaves are arranged alternately with stipules at the petiole base. The leaves are compound with 3 leaflets that are ovate to oblong in shape with an acute leaf apex and entire margin. The leaves are often covered with hairs.
The complete, perfect, zygomorphic flowers, on short pedicels, are arranged in racemes that can be up to 30 cm in length. The calyx has 5 fused sepals that are greenish and form a short tube. The corolla has 5 dark pink to purple red petals that are fused at their base. There are 2 petals forming a keel and a single large petal that is the standard. There are 10 stamens with 9 of them fused forming a partial tube around the ovary. The ovary is superior with a single locule. Around the base of the ovary is a short nectary. The fruit is an elongate linear legume with brown-grey seeds with black speckles. The fruit twists as it matures and is elastically dehiscent.
Habitat: Macroptilium lathyroides is considered a weedy species growing in Human Altered environments such as old fields, roadsides, and abandoned farms.
Distribution: Macroptilium lathyroides grows throughout the islands of the Lucayan Archipelago as well as the entire Caribbean region, and Central and South America.
Medicinal/Cultural/Economic usage: Macroptilium lathyroides is not known to be used medicinally in the Lucayan Archipelago.
Macroptilium lathyroides has been used as a forage species in some areas. It is also a known nitrogen fixer and thus has been useful for soil amendment.