ニレ科ケヤキ属の落葉高木で、学名は Zelkova serrata。英名は Japanese zelkova。
The Japanese zelkova (Zelkova serrata) belongs to Ulmaceae (the Elm family). It is a tall deciduous tree that is distributed from Honshu to Shikoku, Kyushu in Japan, as well as Taiwan, the Korean Peninsula and China. This tree grows in temperate forests or warm-temperate forests and can reach 20-25 m in height. The trunk is erect and the branches spread broom-like. The barks are grayish-white and furrowed into large scaly ridges when aging. The leaves are narrow-ovate to ovate and alternate with acute toothed edges. It is dioecious. The inconspicuous yellowish-green flowers come in April to May. The leaves turn red in fall. Its Japanese name comes from the fact that it was said to be a "keyakeki (outstanding) tree". It was also called "tsuki" in ancient times, and the name of Takatsuki City in Osaka comes from "a large tsuki tree". It is called "欅" in Taiwanese Chinese and "欅樹" (ju shu) in Chinese.