A legume (/ˈlɛɡjuːm/ or /ˌləˈɡjuːm/) is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. Legumes are grown agriculturally, primarily for their food grain seed (example beans and lentils, or generally pulse), for livestock forage and silage, and as soil-enhancing green manure.Legumes are notable in that most of them have symbiotic nitrogen-fixing bacteria in structures called root nodules. legume fruit is a simple dry fruit that develops from a simple carpel and usually dehisces (opens along a seam) on two sides.