pulse, in botany, common name for members of the Fabaceae (Leguminosae), a large plant family, called also the pea, or legume, family. Numbering about 650 genera and 17,000 species, the family is third largest, after the asters and the orchids. Some botanists divide the Fabaceae into three or more separate families, but most species share certain common and easily recognizable features. The leaves are usually compound; the fruit is a legume (a type of pod); and the blossoms may have an irregular butterflylike (papilionaceous) shape. Typically, the flowers have 10 stamens, and the corolla and the calyx are formed of 5 petals and 5 sepals, respectively. Some species have thorny branches.
The Fabaceae include herbs, shrubs, and trees distributed throughout the world in a great variety of forms. Arboreal species occur in temperate and, frequently, in tropical zones, where epiphytic and climbing forms also thrive. Many leguminous shrubs and trees inhabit desert and semiarid regions, usually forming the characteristic vegetation—e.g., the acacias of the S African bushveld and of Australia, and the mesquite of the American Southwest.
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