They are grown in Asia, Africa and India.
The colour can be yellow, red, brown or black: though yellow or red are the most common. Whatever the colour, they will have a white, raised spot on the side.
Asian Rice Beans grow on hairy vines that blossom with yellow flowers. The pods hang downwards as they develop and tend to break open and drop the beans. When the pods are dry, they tend to break open even during harvesting.
The dried beans can be cooked and eaten with rice. Asian Rice Beans can also be used to make sweet dishes. They have a very soft texture when cooked.
Asian Rice Beans are not cultivated much in Japan anymore; the Japanese will import them from other places such as Thailand (mainly) and Burma (aka Myanmar.)
Nutrition
Asian Rice Beans are very high in calcium content.
History Notes
Asian Rice Beans are native to South East Asia. In northern Thailand, some tribes would lightly boil the young pods, and eat them whole with salt.