Phaseolus coccineus

Phaseolus coccineus, known asrunner bean,scarlet runner bean,ormultiflora bean,is a plant in the legume family,Fabaceae. Another common name isbutter bean,which, however, can also refer to thelima bean, a different species.
It is grown both as a food plant and anornamental plant.
This species originated in the mountains ofCentral America. It was most likely cultivated in the highlands of Mexico and Guatemala around 2000 BC.Most varieties have redflowersand multicoloredseeds(though some have white flowers and white seeds) and are often grown asornamental plants. The vine can grow to 3 metres (9.8 ft) or more in length,its pods can get to  25 centimetres (9.8 in), and its beans can be up to 2.5 centimetres (0.98 in) or more.
It differs from thecommon bean(P. vulgaris) in several respects: thecotyledonsstay in the ground duringgermination, and the plant is aperennialvinewith tuberousroots(though it is frequently treated as an annual in colder climates).
The knife-shaped pods are normally green; however, there are rare varieties bred by amateurs that have purple pods. An example of such a purple-podded runner bean is 'Aeron Purple Star'.
Runner beans have also been called "Oregon lima bean",and inNahuatlayocotlor in Spanishayocote. Runner beans, like allbeans, contain thetoxicproteinphytohaemagglutininand thus should be cooked well before eating.
Runner beans were grown as food plants in North America and Europe from the 1600s, and also as ornamentals for their attractive flowers. However, they came to be used primarily as a garden ornamental plant in North America, including for temporary screening. The flowers attracthummingbirds, bees and other insects. In the UK and other European countries – where the vegetable is a popular choice for kitchen gardens and allotments – the flowers came to be ignored, or treated as an attractive bonus to cultivating the plant for the beans.
The seeds of the plant can be used fresh or as dried beans. The pods are eaten whole while young and not yet fibrous, though they tend to have a rougher surface than thecommon bean. The starchy roots of this perennial are eaten inMesoamerica.
The beans are used in many cuisines. It is a popular side vegetable in British cuisine. A variety named 'Judión de la Granja' producing large, white, edible beans is cultivated inSan Ildefonso, Spain.It is the basis of aSegovianregional dish also namedJudiones de la Granja, in which the beans are mixed withpig's ears,pig's trotters, andchorizo, amongst other ingredients.
In Greece, cultivars of the runner bean with white blossom and white beans are known asfasolia gigantes(φασόλια γίγαντες). They are grown under protective law in the north of Greece within the regions ofKato Nevrokopi,FlorinaandKastoria.The beans have an important role in Greek cuisine, appearing in many dishes (such asGigantes plaki). In English, they are sometimes colloquially referred to as elephant beans.In Austria the coloured versions are cultivated and served as "Käferbohnen" ("beetle-bean"), a dish made of the dry beans withpumpkin seed oil. It is considered a typical dish of regional Austrian cuisine, but dried runner beans are also consumed to a small extent in Germany. In Turkey, runner beans are the main ingredient in beanPilakiandPiyaz.
Greece and northern Africa are the sources of pods of the runner beans sold as "green beans" in European markets during the cold period. The pods can be identified by their big size and the rougher surface.
Cultivarsinclude:
P. coccineussubsp.darwinianusis a cultivated subspecies, commonly referred to as thebotilbean in Mexico.
The related species considered most useful for interbreeding withP. coccineusto increase its genetic diversity areP. dumosusandP. vulgaris.