ニレ科ニレ属の落葉高木で、学名は Ulmus davidiana var. japonica (syn. Ulmus propinqua、Ulmus japonica)。英名は Japanese elm。
The Japanese elm (Ulmus davidiana var. japonica) belongs to Ulmaceae (the Elm family). It is a tall deciduous tree that is distributed throughout Japan, as well as the Korean Peninsula, northeastern and northern China. This tree grows in hillsides to mountains, and can reach 20-30 m in height. The barks are gray, furrowed longitudially and into large scaly ridges. The leaves are obovate and arranged in alternate with double-serrated margins. The small flowers bloom on the axils of new branches from March to May. The fruits are samaras and ripen in early summer. The timbers are used as furnitures and floor covers. In Chinese, it is called "春楡" (chun yu).
In Korean, it's called "neu-reum-na-mu" (느릅나무). It is believed that this name originated from the fact that soaking the bark in water produces a sticky mucus, leading to the word "neu-reum" (느름) evolving into "neu-reup" (느릅).