Phaseolus vulgaris, also known as the common bean, is a herbaceous annual plant grown for its edible dry seeds or unripe fruit. The main categories of common beans are dry, snap and shell beans. Beans are grown on every continent except Antarctica.
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, 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. The common bean is a highly variable species with a long history. Bush varieties form erect bushes 20–60 cm (8–20 in) tall, while pole or running varieties form vines 2–3 m (7–10 ft) long. All varieties bear alternate, green or purple leaves, which are divided into three oval, smooth-edged leaflets, each 6–15 cm (2–6 in) long and 3–11 cm (1–4 in) wide. The white, pink, or purple flowers are about 1 cm long, and they give way to pods 8–20 cm (3–8 in) long and 1–1.5 cm wide. These may be green, yellow, black, or purple in color, each containing 4–6 beans.