Runner bean (scientific name Phaseolus coccineus) is also known as multiflora bean or scarlet runner bean. This plant is a member of the Fabaceae or legume family. Runner bean is cultivated as a food plant as well as an ornamental plant. Hummingbirds have a special preference for the flowers of this plant.
Compared to all other plants in the legume family, this bean plant is most productive. The yield of this plant will be excellent provided it is grown in a place having warm climatic conditions. On the contrary, runner bean plants do not have a good yield when grown in hot areas or cold regions.
According to available documents, Phaseolus coccineus has its origin in the mountainous regions of Central America. Nearly all varieties of this species bear red flowers and produce multicoloured seeds. However, some even bear white flowers and produce white seeds. Often these plants are cultivated for their ornamental value. Phaseolus coccineus is a vine that can grow up to a length of about 3 meters and sometimes even more.
Precisely speaking, runner bean plants are long and twisted perennially growing vines, which are cultivated in the form of annuals both for their edible pods and seeds as well as their ostentatious blossoms. The roots of runner beans are thick and stocky and the vines can grow up to a length of 3.5 meters and sometimes even longer. The leaves of Phaseolus coccineus are trifoliate and all the leaflets are broadly oval, measuring anything between 10 cm and 12.7 cm in length. Nearly all cultivars of this species bear bright scarlet red hued flowers, whose shape is similar to the characteristic bean flowers. The two petals at the base of the flowers fuse to form the "keel", while the topmost petal is modified to form a "standard" resembling a hood. The petals on the side are transformed to form spreading "wings".
The flowers of runner bean measure roughly an inch in length and appear in a clustered form in racemes that are about 25 cm long. A single flower stock of this plant may bear up to 20 flowers. Each runner bean plant may produce numerous pods or legume, each measuring 15 cm to 20 cm. The seeds of this plant measure around an inch and each pod may contain anything between 6 to 10 seeds. The "Scarlet Runner" is the most familiar runner bean cultivar. This cultivar bears red flowers, while its mottled seeds are burgundy and black.
On the other hand, the flowers of the cultivar called "Black Runner" are intense crimson and the plant produces jet black seeds. The flowers of the "Painted Lady" cultivar have red standards, while their wings and keels are white. The "Case Knife" and "White Dutch Runner" bear white flowers, which give way to pods containing white hued seeds. New stringless cultivars like the "Polestar" and "Butler" bear pods that are significantly long and measure about 30.5 cm. Conversely, cultivars like "Pickwick Dwarf" and "Hammond's Dwarf" are non-climbing plants. These cultivars are like bushes and they even mature two to three weeks earlier compared to the running cultivars.
There are several differences between the runner bean and the common bean (scientific name P. vulgaris) plants. Unlike the common bean, the cotyledons of runner bean remain in the ground during the germination period. Moreover, plants of this species are perennially growing vines having tuberous roots. However, the plants belonging to the runner bean family are considered to be annual plants.
Runner beans, also known as "Oregon lima bean", are also called ayocote in Spanish and ayocotl in Nahuatl. Similar to all other varieties of beans, runner beans also contain a toxic protein called phytohaemagglutinin. Hence, it is essential that you cook these beans well before consumption.
Many people grow runner beans in their gardens/ yards as the flowers of this plant are ornamental in appearance. You can use the seeds of this species fresh or even as dried beans. Generally, the pods are also edible. Runner bean plants grow very well on the ground and, hence, there is no need to put them on trellis. Plants of this species have a preference for fertile and moist soils. The roots of runner bean are starchy and, therefore, edible. It takes about 90 days or three months from the day of sowing for the fruits of runner bean become mature.
Since the runner bean is a perennially growing plant, the thickened and plump roots of this plant go into hibernation when grown in warmer climatic conditions. In fact, these roots are edible and can be consumed for their nutritional value. However, the roots of runner bean should only be eaten after they have been cooked properly. When grown in places having moderate climatic conditions and the thickened roots of the plant are grown in a creative manner, they only help in vegetative reproduction of the species. The roots remain healthy when the substratum is humid, at temperatures around 5�C.
While the green pods of runner beans are edible as a whole, pods of a number of varieties, like the scarlet runner, have a tendency to turn fibrous very early in their growth and, hence, you can only consume the seeds of such plants. You can use these seeds fresh as well as in their dried forms. Native Indians of Central America eat the starchy roots of these plants even to this day. In the United Kingdom, people usually ignore the flowers of runner bean or simply consider them to be an added bonus owing to their ornamental look. On the other hand, people in the United States only grow the scarlet runner for its showy flowers and never even consider consuming the beans or pods.
The edible seeds and pods of runner beans offer us a number of health benefits. They are an excellent natural resource of vitamin K, which is essential for the health of our bones. Vitamin K is useful in preventing any damage to the bones. Any deficiency of this vitamin in the body augments the risks of bone fractures.
Runner beans also possess potent diuretic properties. Therefore, consuming runner bean seeds and pods helps to promote urination, thereby eliminating toxins from our body.
Aside from possessing diuretic properties, runner beans are also effective antioxidants. The antioxidant properties of these beans make them a valuable food for the health of our heart. The antioxidants shield the heart from any damage due to oxidation and, at the same time, enhance the level of fats in the blood stream. These beans are also good for the health of our cardiovascular system.
Runner beans also enclose significant levels of dietary fibers that are useful in lowering the levels of bad or LDL cholesterol in the blood stream. Runner beans also contain varying amounts of essential minerals like magnesium and potassium. These minerals are helpful in keeping the blood pressure levels in check.
Runner beans also contain several other essential minerals, including calcium, manganese, and iron. These minerals are necessary for proper metabolism in our body. Moreover, manganese is actually a co-factor for the antioxidant enzyme called superoxide dismutase. This antioxidant enzyme is effective in getting rid of free radicals from our body.
Similarly, potassium is a vital cell constituent and also has an important function in the body fluids, as it aids in controlling blood pressure and the heart rate.
Runner beans are also an excellent source of various vitamins, including vitamin C, vitamin B1 (thiamine) and vitamin B6 (pyridoxine). Vitamin C is useful for our body since its aids in developing defence against various infectious agents. This vitamin also helps to effectively neutralize the destructive free radicals.
These beans also enclose folate and vitamin B12 - one of the essential substances for DNA synthesis as well as cell division. In fact consumption of runner beans during pre-conception as well as during pregnancy is helpful in putting off defects in the neural tube of an offspring.
Even the dried out seed pods of Phaseolus coccineus also possess diuretic properties. Drinking a tea prepared from runner bean pods is useful in treating infections of the urinary tract. At the same time, it also helps to reduce weight.