Fabaceae, formerly named Leguminosae, the Pea family, includes over 16,000 species of trees, shrubs, climbers, and herbaceous plants worldwide. These plants are particularly valuable as crops because they do not require nitrogenous fertilizer, and even enrich the nitrogen content of the soil.
The flowers are butterfly-like, with 5 unequal petals, an upright banner, a side pair of wings and 2 joined inner petals forming a keel, which envelops the stamens and pistil. There are 10 stamens, joined to a pipe, and 1 pistil. The family is characterized by the fruit, technically known as a legume or pod, which when ripe opens along both margins to release the seeds. The leaves of the Pea family bear stipules (outgrowths at the base of the leaf stalk) and are often compound, usually pinnately compound, sometimes with tendrils (thread-like outgrowths used for climbing) at the leaf tips. Another distinctive feature of the family is the presence of root nodules containing rhizobium bacteria, which fix atmospheric nitrogen, converting it into forms useful to the plant.