Legumes

A legume is the pod of a plant such as peas, beans or vetches, which all belong to the same family of plants (Leguminosae, or Fabaceae). Legumes provide a vital source of food for humans and their animals. They are high in protein and contain many of the essential amino acids. People get protein from peas, beans, peanuts and soybeans while their animals get it from alfalfa (lucerne) and clovers, which is then passed on to the humans when they eat their animals.

Legumes get the nitrogen they need to make these amino acids from symbiotic Rhizobium bacteria which live in nodules on their roots. These bacteria are able to fix nitrogen, transforming atmospheric nitrogen into nitrates and other compounds, some of which are passed on the legume. In return the legume gives protection and food to the bacteria. These compounds are also available to other plants after decayed roots (and other plant parts) of the legume have released these nitrogen products into the soil. Animals get nitrogen compounds by eating plants.

We also extract edible oils, fibers, and raw material for plastics from them.

Seeds of the Phaseolus beans and other legumes produce phytohemagglutinin, a protein that clots certain human blood types and has other medical applications.