Ulmus pumila L. is a deciduous tree species belonging to the genus Ulmus in the family Ulmus. The bark of the young tree is smooth, while the bark of the large tree is dark gray; Winter buds are nearly spherical or oval in shape; Leaves are elliptical and ovate in shape, with smooth and hairless leaves. The back of the leaves is covered in short hairs when young, and the petiole surface is covered in short hairs; The samara is nearly round in shape; The flowering and fruiting period is from March to June. Shuowen ":" Yu, Jian. From wood, Yu sound. "Yu is a canoe, and elm wood is a good material for making canoes. Therefore, the characters" wood "and" Yu "refer to elm wood as a tree species for making canoes, and elm trees are named after it.