Leguminosae

Leguminosae, also known as Fabaceae, is a large family of flowering plants in the order Fabales. It includes roughly 700 to 750 genera and about 19,000 species, distributed worldwide in a variety of habitats, from temperate grasslands to tropical forests.

The fruit is a legume, a dry, dehiscent pod that typically splits along two sutures to release the seeds. Leaves are usually compound, often pinnate or trifoliate, with stipules. The flowers are diverse, but many species have irregular, zygomorphic flowers in the subfamily Faboideae, or small, dispersed blossoms in Mimosoideae and Caesalpinioideae. A common feature across many legumes is a symbiotic association with rhizobial bacteria in root nodules, enabling biological nitrogen fixation.

Subdivisions: Historically divided into three main subfamilies—Caesalpinioideae, Mimosoideae, and Faboideae (also called Papilionoideae). In modern classifications, the circumscription can vary, but the major lineages remain. The family is ecologically diverse, occupying a wide range of soils and climates.

Economic and ecological significance: Legumes are a major source of protein and edible oils (soybean, peanut, chickpea, lentil, common bean, pea). They also serve as forages and fodder crops (alfalfa, clover) and as rotation crops that replenish soil nitrogen. Some species provide timber, gum, or ornamental values, and many are used for landscaping and forestry.

Conservation and research: Studying Leguminosae informs agriculture, ecology, and soil science; some species are threatened by habitat loss, while others are invasive in some regions.