Soybean (alias: soybean, soybean and soybean) is an annual herb of Leguminosae, with a height of 30-90 cm. The protein content of soybean is 35% ~ 40%. Stems are stout, erect and densely covered with brown bristles. Leaves usually 3-foliolate; Stipules veined and yellow pilose; Petiole 2-20 cm long; Leaflets broadly ovate, papery; Racemes are short with few flowers and long with many flowers; The total pedicel usually has 5-8 sessile, tightly packed flowers.

Bracts lanceolate, strigose; Bracteoles lanceolate, appressed bristles; Calyx is lanceolate, with purple, lavender or white flowers, pedicel at the base, and petaloid wings. Pods are fat, slightly curved, drooping, yellow-green, densely covered with brown-yellow long hair; 2-5 seeds, oval, nearly spherical, smooth seed coat, light green, yellow, brown and black and so on. The flowering period is from June to July, and the fruiting period is from July to September.

Cultivation history:

China has been cultivated since ancient times, with a planting history of 5,000 years. It is widely planted in China, and it is produced in Northeast China, North China, Shaanxi, Sichuan and the lower reaches of the Yangtze River. It is cultivated in the Yangtze River Basin and Southwest China, and the quality of soybeans in Northeast China is the best.

Introduced to the United States in 1804; In the middle of the 20th century, it became an important crop in the southern and midwest of the United States. Soybean cultivated all over the world is directly or indirectly spread from China. Because of its high nutritional value, it is called "king of beans", "meat in the field" and "green milk", and it is the most respected food among hundreds of natural foods.