Phaseolus vulgaris
Phaseolus vulgaris, also known as the common bean[2] and French bean,[3] is a herbaceous annual plant grown worldwide for its edible dry seeds or unripe fruit (both commonly called beans). The main categories of common beans, on the basis of use, are dry beans (seeds harvested at complete maturity), snap beans (tender pods with reduced fibre harvested before the seed development phase) and shell (shelled) beans (seeds harvested at physiological maturity). Its leaf is also occasionally used as a vegetable and the straw as fodder. Its botanical classification, along with other Phaseolus species, is as a member of the legume family Fabaceae. Like most members of this family, common beans acquire the nitrogen they require through an association with rhizobia, which are nitrogen-fixing bacteria.
The common bean is a highly variable species that has a long history of cultivation. All wild members of the species have a climbing habit,[4][5] but many cultivars are classified either as bush beans or dwarf beans, or as pole beans or climbing beans, depending on their style of growth. These include the kidney bean, the navy bean, the pinto bean, and the wax bean.[6] The other major types of commercially grown bean are the runner bean (Phaseolus coccineus) and the broad bean (Vicia faba). Beans are grown on every continent except Antarctica. Worldwide, 27 million tonnes of dried beans and 24 million tonnes of green beans were grown in 2016.[7] In 2016, Myanmar was the largest producer of dried beans, while China produced 79% of the world total of green beans.
The wild P. vulgaris is native to the Americas. It was originally believed that it had been domesticated separately in Mesoamerica and in the southern Andes region, giving the domesticated bean two gene pools.[8] However, recent genetic analyses show that it was actually domesticated in Mesoamerica first, and traveled south, probably along with squash and maize (corn). The three Mesoamerican crops constitute the “Three Sisters” central to indigenous North American agriculture.[9]
