_Phaseolus multiflorus_, scarlet runner, is nearly allied to _P. vulgaris_, of which it is sometimes regarded as a variety, but differs in its climbing habit. It is naturally perennial and has a thick fleshy root, but is grown in Great Britain as a tender annual. Its bright, generally scarlet flowers, arranged in long racemes, and the fact that it will flourish in any ordinary good garden soil, combine to make it a favourite garden plant. It is also of interest as being one of the few plants that twine in a direction contrary to the apparent motion of the sun. The seeds of the runner beans should be sown in an open plot,--the first sowing in May, another at the beginning of June, and a third about the middle of June. In the London market-gardens they are sown 8 to 12 in. apart, in 4 ft. rows if the soil is good. The twining tops are pinched or cut off when the plants are from 2 to 2½ ft. high, to save the expense of staking. It is better, however, in private gardens to have the rows standing separately, and to support the plants by stakes 6 or 7 ft. high and about a foot apart, the tops of the stakes being crossed about one-third down. If the weather is dry when the pods are forming abundantly, plenty of tepid water should be supplied to the plants. In training the shoots to their supports, they should be twined from right to left, contrary to the course of the sun, or they will not lay hold. By frequently picking the pods the plants are encouraged to form fresh blooms from which pods may be picked until the approach of frost.
The ordinary scarlet runner is most commonly grown, but there is a white-flowered variety which has also white seeds; this is very prolific and of excellent quality. Another variety called Painted Lady, with the flowers red and white, is very ornamental, but not so productive. Carter's Champion is a large-podded productive variety.
Another species _P. lunatus_, the Lima bean, a tall biennial with a scimitar-shaped pod (whence the specific name) 2 to 3 in. long containing a few large seeds, is widely cultivated in the warmer parts of the world.
The young pods of another leguminous climbing herb, _Dolichos Lablab_, as well as the seeds, are widely used in the tropics, as we use the kidney bean. The plant is probably a native of tropical Africa, but is now generally cultivated in the tropics. The word _Dolichos_ is of Greek origin, and was used by Theophrastus for the scarlet runner.