Phaseolus vulgaris

climbing bean


Phaseolus vulgaris 'Purple Champion'

L. 1753

pronounced: FAZ-ee-oh-luss vul-GAR-iss

(Fabaceae — the pea family)

subfamily: Faboideae - the bean subfamily

common name: climbing bean

Phaseolus is derived from the Greek φασηλος (phasélos), a light boat, a sort of bean; vulgaris is Latin for common, ordinary, every-day.

‘Purple Champion’ is a cultivar of the common bean, domesticated in the Andes and in Mexico in ancient times, and now grown worldwide. Although the beans are purple when ripe, they turn green when they are cooked. The common bean is one of the most important domestic legumes, because of its high concentrations of proteins, fibres, and complex carbohydrates. It is one of the “three sisters” of traditional cropping methods of north American natives – maize, squash and beans – reported by early colonists there. There are two different wild strains: the Andean gene pool is found from southern Peru to north-western Argentina, and the Middle American gene pool from Mexico through Central America and into Venezuela. The two gene pools diverged some 11,000 years ago. In general, the seeds from the latter pool are smaller than those from the former.

The common bean is a highly variable species. Bush varieties are erect plants 20 – 60 cm tall, while pole or running varieties form vines up to about 3 m long. Whatever the variety, the trifoliate leaves are alternate, coloured green or purple, and divided into 3 oval, smooth-edged leaflets, each leaflet 6 – 15 cm by 3 – 11 cm wide. The flowers may be white, pink or purple, are small, only about 1 cm long, and produce pods 8 – 20 or so cm in length, each usually containing 4 – 6 beans. The beans are smooth, plump, and reniform, up to 15 mm long. The colour of the beans varies widely (green, black, yellow, purple), and they are often mottled in two or more colours.

dangerous 2Large quantities of the raw mature seeds are poisonous, the toxins playing a role in protecting the plant from insect predators. Children eating just a few raw seeds have shown mild forms of poisoning, with nausea and diarrhœa, but no deaths are known to have occurred.

The common bean species includes:

      • dry beans, with many varieties including pintos. They are used for soup, salads and chili. The actual beans are slow-maturing, and stay green longer than those of shell beans.

      • snap beans, a.k.a. string beans or french beans. These are eaten pod and all. Until about a hundred years ago, the pods had tough strings that had to be removed before cooking, but now most varieties marketed are stringless.

      • shell beans, including black beans, garbanzo beans, lima beans, red kidney beans and fava beans. Shell beans are like dry beans, but mature more quickly. Fava beans are thought to be the beans in the iron rations God, through Ezekiel, told the Children of Israel to take into exile. Pythagoras (570 – 495 BC) blamed fava beans for insomnia and bad dreams – perhaps he suffered from favism, a rare inherited allergy to broad beans that mostly occurs in males of Mediterranean descent.

      • popping beans, or ñuñas as they are called in Peru, whose seeds expand upon toasting. They are a popular snack in parts of Peru and Ecuador.

The Climbing Bean is a food source for quite a few caterpillars, including:

      • the Tomato Grub Helicoverpa armigera;
      • the European Painted Lady Vanessa cardui;
      • the Comoin Grass Blue Zizina labradus;
      • the Dark Cerulean Jamides phaseli;
      • the Cupid Euchrysops cnejus;
      • the Bean Looper Mocis alterna; and
      • the Tobacco Looper Chrysodeixis argentifera.


Photographs taken at Picnic Bay 2012
Page last updated 9th March 2019