Phaseolus vulgaris, the common bean,, is a herbaceous annual plant. Its botanical classification, along with other Phaseolus species, is as a member of the legume family, Fabaceae. It forms a green-leaved vine which produces beans inside of pods.
All wild members of the species have a climbing habit, but many cultivars are classified either as bush beans or climbing beans, depending on their style of growth. In 2022, 28 million tonnes of dry common beans were produced worldwide, led by India with 23% of the total.
The common bean is the most consumed bean species in the world and is native to the Americas. It was domesticated in Mexico, Central America and the southern Andes region some ago. It has many cultivars.
Raw dry beans contain the toxic compound phytohaemagglutinin, which can be deactivated by boiling the beans for 30 minutes. In addition to the beans, the unripe green pods are used for food. The leaf is occasionally used as a vegetable and the straw as fodder.
Description
Bush varieties form erect bushes tall, while pole, or running, varieties form vines long. All wild members of the species have a climbing habit. All varieties bear alternate, green or purple leaves, which are divided into three oval, smooth-edged leaflets, each long and wide.
The white, pink, or purple flowers are about a centimetre long and have 10 stamens each. The flowers are self-pollinating, which facilitates the selection of stable cultivars. The flowers give way to pods long and 1–1.5 cm wide. These may be green, yellow, black, or purple, each containing 4–8 beans. Some varieties develop a string along the pod; these are generally cultivated for dry beans, as green stringy beans are not commercially desirable. The beans are smooth, plump, kidney-shaped, up to 1.5 cm long, range widely in color and are often mottled in two or more colors. The beans maintain their germination capacity for up to five years.
Like most Phaseolus species, the genome has 11 chromosomal pairs (2n = 22). The genome is one of the smallest in the legume family at 625 Mbp per haploid genome.
Raw or undercooked beans contain a toxic protein called phytohaemagglutinin.
Taxonomy The common bean, like all Phaseolus species, is a member of the legume family, Fabaceae.
In Species Plantarum in 1753, Carl Linnaeus classified the beans known by him into genus Phaseolus and genus Dolichos, naming 11 species of Phaseolus, including 6 cultivated species and 5 "wild" species.
The beans cultivated in Europe prior to the Columbian Exchange were of Asian origin and are unrelated to New World Phaseolus species. The Eurasian species were transferred to other genera including Vigna, Vicia and Lablab, so members of the Phaseolus genus are now all from the Americas.
Etymology Ancient Greeks used the word () to refer to the beans of Asian origins that were cultivated in Europe at the time.PDF The Romans used both the Latinized phaseolus and their own faba to refer to different pre-Columbian species of beans, presumably using the word faseolus for smaller seeds like those belonging to the genus Vigna such as black-eyed peas and the word faba for larger seeds, such as the fava beans. This latter word, faba, was related to the Proto-Germanic bauno, from which the Old English word is derived and has the meaning of "bean, pea, legume". When Phaseolus vulgaris arrived in Europe in the 16th century, this species was yet another seed in a pod, thus there were already words in the European languages describing it.
In the Americas, P. vulgaris is also known as in Nahuatl (Aztec language), in Mayan (Maya language) and in Quechua (Inca language). In Argentina, Bolivia, Chile, Paraguay and Uruguay, the Spanish name is used, being derived from its corresponding Quechua word. Additional names include the Castilian Spanish , the Portuguese , and the Catalan .
Distribution
Wild P. vulgaris is native to the Americas. It was domesticated separately in Mesoamerica and in the southern Andes region some ago, giving the domesticated bean two gene pools.
Beans, squash, and maize (corn) are the three Mesoamerican crops that constitute the "Three Sisters", central to indigenous American agriculture.
The common bean arrived in Europe as part of the Columbian exchange. It is now grown on every continent except Antarctica.
Ecology Like most members of Fabaceae, common beans acquire the nitrogen they require through an association with rhizobia, which are nitrogen-fixing bacteria.
Cultivation Good commercial yield in favorable environments under irrigation is fresh and dry seed.
Cultivars and varieties Archeologists found large-seeded varieties of the domesticated bean in the highlands of Peru, dating to 2300 BC, and spreading to the coastal regions by around 500 BC. Small-seeded varieties were found in sites in Mexico, dating to 300 BC, which then spread north and east of the Mississippi River by 1000 AD.
Many well-known bean cultivars and varieties belong to this species, and the list below is in no way exhaustive. Both bush and running (pole) cultivars/varieties exist. The colors and shapes of pods and seeds vary over a wide range.