Red bean is a big category in botany, involving at least six kinds of plants, in order to correct some misconceptions of people, it is briefly described as follows:
1. Vine acacia, not the red bean in Wang Wei's poem (the seeds are half-red and half-black)
Acacia (Abrus precatorius): Leguminosae. Woody vines. Branches thin and weak. Spring and summer flowering, butterfly-shaped corollas, often pale red or purple, in racemes. Pods long ellipsoid. Seeds broadly ovoid, vermilion at upper end, black at lower end. Distributed in tropical Asia; also in S China. Seeds scientific name of chicken mother beads, highly toxic, commonly used as a traditional Chinese medicine.
2. Evergreen tree red bean tree, alias Acacia, real red beans, Acacia (seeds all red)
Red bean tree (Ormosia hosiei): Leguminosae. Trees. Spring flowering, butterfly-shaped corolla, white or light red, panicle. Pods woody, long oval, seeds bright red, shiny. Produced in central and eastern China for ornamental purposes; the wood is heavy, red, with a beautiful pattern, and is excellent for carving and joinery.
3. Deciduous tree sea red bean, alias Acacia, real red beans, Acacia (seeds all red)
Sea red bean (Adenanthera pavonina): also known as "Acacia gram", "Acacia tree ", "peacock bean". Leguminosae. Deciduous trees. Flowers small, white or yellowish, in narrow racemes. Pods curved and convoluted at maturity. Seeds convex mirror-shaped, bright red. Philippines, Vietnam, Malaysia, Indonesia, India, Sri Lanka; also in Guangdong, Hainan, Guangxi, Yunnan, and E Himalayas, China. The wood is hard, the heartwood is slightly coarse-grained, and resistant to water and moisture. It is an excellent timber for shipbuilding, and can be used for construction, furniture, gun stocks and other timber. Seeds bright red, crystalline as coral, southern people often used to inlay jewelry.
4. Adzuki beans, also known as red beans, red beans are vegetables, and love and love have nothing to do (dark red seeds)
Adzuki beans (Phaseolus angularis): the ancient name of the "small peas", "red peas," commonly known as "red beans". "red beans", "red beans", "red beans", "red beans", "small beans". Leguminosae. Annual herbs. Flowers yellow or pale gray. Pods glabrous, seeds elliptic or long elliptic, generally russet. Native to Asia; widely cultivated in China. Seeds rich in starch, protein and B vitamins, etc., can be used as food and foodstuffs, and can be used medicinally, is a tonic. See below for more information.
5. Acacia confusa, Taiwan, does not grow acacia beans (seeds dark brown)
Taiwan Acacia confusa (Acacia confusa): Leguminosae. Evergreen tree. Up to 15 m tall. blooms from April to October, head-like inflorescences with golden-yellow flowers. Pods strap-shaped, flattened. Seeds dark brown, shiny. Distributed in Taiwan, China, south of central Fujian and the hills and plains acidic lands of Guangdong and Hainan. The wood is solid, delicate, and durable, and is used for building and making agricultural tools. The bark is used to extract tannins. It is also a roadside tree and an ornamental tree in South China.
6. Taxus wallichiana zucc, not belonging to the legume family, has nothing to do with the red bean (the seeds are red)
Taxus wallichiana zucc: the red bean tree family. Evergreen tree. Branchlets turn yellowish green or light reddish brown until fall. The seeds are flat-ovate, with an inconspicuous ribbed back on each side, surrounded by a red fleshy cup-shaped aril. It is endemic to China, distributed in Gansu, Shaanxi, Hubei, and Sichuan, Yunnan. The wood can be used as timber for building, boat, furniture, utensils, etc.; the seeds are pressed for oil.