Red bean tree is an evergreen or deciduous tree of Leguminosae and Red Bean, also known as Why Red Bean, Red Bean in Western Hubei, Red Bean in Jiangyin and Red Sandalwood. This kind of tree is very tall, it can grow to 30 meters high, and the DBH of its trunk can reach one meter. Because its seed skin color is bright red, it is named red bean tree. Young adzuki bean trees have unique gray-green bark with gray lenticels, and the old bark is dark gray brown. The leaves are odd-numbered pinnate compound leaves, thin leathery ovate or elliptic, sharp or acuminate at the apex, rounded or broadly wedge-shaped at the base. Like the leaves of many plants, adzuki bean trees have two different colors. The upper leaves are dark green and the lower leaves are light green. The newly grown leaves of red beans are sparse, and when they get old, they will become smooth or only have sparse hairs on the midvein of the lower leaves.