Rice bean ( Vigna umbellata )
|( Thunb. ) Ohwi & H.Ohashi|
The rice bean ( Vigna umbellata ) is a plant of the subfamily Schmetterlingsblütler (Faboideae) within the family of the Leguminosae (Fabaceae or Leguminosae). This globally insignificant crop is closely related to a number of other crops called " beans " . The German trivial name is a translation of the English ("Rice Bean"), which expresses the method of preparation similar to rice .
The wild form of the rice bean occurs from central China to Southeast Asia , south from the Himalayas to Malaysia. In the same area, the cultivated forms were traditionally grown. Today it is also used on many tropical islands in the Pacific and in Africa. The precipitation can be between 700 and 1700 mm.
The rice bean is a very fast growing and very early ripening annual herbaceous plant . It grows upright to slightly hanging and reaches heights of about 30 to 70 cm or stronger growing varieties with twisting or lying stems that can be up to 3 meters long. The stems have stiff, short white hairs (trichomes). The leaves usually have 2 to 15, rarely up to 37 cm long stems and three-part leaf blades. The long-oval to lanceolate partial leaves are 5 to 10 cm long and 2.5 to 6 cm wide. The leaf margins are usually smooth or the lateral part leaves can also be slightly three-lobed. The stipules are 8 to 12 mm in size.
The axillary on 5 to 20 cm long stems contain racemose inflorescences , each grouped in twos or threes on a node, a total of five to 20 flowers. The bracts are about 2.5 to 3.0 mm long and the bracts at the base of the sepals are 3 to 3.5 mm long. The hermaphrodite flowers are zygomorphic . The downy, hairy calyx is about 4 mm long with five calyx teeth about 2 mm long. The five petals are (light) yellow. The curved flag is 9 to 12 mm in size. Mostly self-fertilization occurs.
The long, slender, hairless legumes have a length of 6 to 12 cm and a diameter of about 0.5 cm. The ripe legumes burst easily. Each legume usually contains six to eight, at most twelve seeds. The oblong, rectangular, with typical rounded corners, seeds are about 5 to 10 mm long and 2 to 5 mm thick. The thousand grain weight fluctuates between mostly 30 and 120 at most up to 230 grams. The color of the bean seeds varies between yellow, bright red-brown and black, there are also speckled shapes with a concave, elongated, white navel, and in India there are also isolated green and green-spotted seeds.
The number of chromosomes is 2n = 22.
Temperatures around 30 ° C, a good water supply and loamy soil offer the best conditions for rapid growth and maturity; The rice bean also thrives at lower temperatures and can also survive drought.
One can use young sprouts, the leaves, the fresh pods, the fresh beans (= seeds) and the dried beans as human food; the latter represent the traditional purpose.
In addition, the rice bean serves as a forage plant (fresh or dried (hay)) and for green manure. The presence of the nitrogen-fixing root nodules plays a major role.
It was first published as Dolichos umbellatus in 1794 in Trans. Linn. Soc. , 2, 339 by Carl Peter Thunberg . The current valid name was 1968 by Jisaburō Ōi & Hiroyoshi Ōhashi in J. Jap. Bot. , 44, 31 published. Synonyms for Vigna umbellata (Thunb.) Ohwi & H.Ohashi are: Phaseolus calcaratus Roxb. , Vigna calcarata (Roxb.) Short , Phaseolus pubescens flower , Phaseolus ricciardus Ten. , Dolichos umbellatus Thunb. , Adzukia umbellata (Thunb.) Ohwi .
Vigna umbellata belongs to the subgenus Ceratotropis in the genus Vigna .
- SI Ali: Papilionaceae in the Flora of Pakistan : Vigna umbellata - Online
- Walter H. Schuster, Joachim Alkämper, Richard Marquard & Adolf Stählin: Legumes for grain use: Grain legumes of the world , Justus Liebig University Gießen, 1998 .: Joachim Alkämper: Information on the rice bean ( Vigna umbellata ) (German)