Phaseolus coccineus

Phaseolus coccineus, known as runner bean,[2] scarlet runner bean,[2] or multiflora bean,[2] is a plant in the legume family, Fabaceae. Another common name is butter bean,[3][4][5] which, however, can also refer to the lima bean, a different species.

It is grown both as a food plant and an ornamental plant.

This species originated from the mountains of Central America. It was most likely cultivated in the highlands of Mexico and Guatemala around 2000 BC.[6] Most varieties have red flowers and multicolored seeds (though some have white flowers and white seeds), and they are often grown as ornamental plants. The vine can grow to 3 m (9 ft) or more in length.[7]

It differs from the common bean (P. vulgaris) in several respects: the cotyledons stay in the ground during germination, and the plant is a perennial vine with tuberous roots (though it is usually treated as an annual).

The knife-shaped pods are normally green; however, there are very rare varieties bred by amateurs that have very unusual purple pods. An example of such a purple-podded runner bean is ‘Aeron Purple Star’.[8]

Runner beans have also been called “Oregon lima bean”,[9] and in Nahuatl ayocotl or in Spanish ayocote. Runner beans, like all beans, contain the toxic protein phytohaemagglutinin and thus should be cooked well before eating.[10]