Alias red beans and wild red beans.

Its source is the seed of leguminous plant adzuki bean.

The plant morphology is an annual erect herb with a height of 90cm. There are obvious long bristles on the stem. Three compound leaves alternate; The terminal leaflet is ovate, 5 ~ 10 cm long and 2 ~ 5 cm wide, the apex is acuminate, the lateral leaflets are oblique, whole or 3-lobed, and both sides are sparsely white pilose; Stipules ovate. Racemes axillary; Calyx 5-lobed; Corolla butterfly-shaped, yellow, flag petal short claw, keel petal upper curl; Stamens 10, dimorphic. The pod is cylindrical and 5 ~ 8 cm long. 6 ~ 8 seeds. The flowering period is from June to July, and the fruiting period is from July to August.

It is widely planted all over the country. Location: Jilin, Beijing, Tianjin, Hebei, Shaanxi, Shandong, Anhui, Jiangsu, Zhejiang, Jiangxi, Guangdong and Sichuan.

When the pods mature and don't crack in autumn, pull out the whole plant, dry it in the sun and sow the seeds.

Trait seeds are oblong, flat at both ends, 5 ~ 7 mm long and 4 ~ 6 mm in diameter. The surface is dark red and shiny, and there is a white linear hilum on the side, about 4mm long and not prominent. The two cotyledons are thick and milky white.