Japan wood-oil tree (Aleurites cordata) belongs to the Euphorbiaceae (the Spurge family). It is a tall deciduous tree that is distribuded from midland of Honshu west to Shikoku and Kyushu of Japan, and the Korean Peninsula, China, Taiwan. The growth of this tree in Japan is unverified to be native or not. In the west of Japan, this tree was cultivated for wood-oil formerly. This tree can reach about 15 m in height. The leaves are ovate to broad ovate, and shallowy 3 lobed and acutely serrated. The panicles are borne and the small whitish,about 2 cm across flowers bloom from May to June. The fruits are oblate nuts and contain 3 seeds. The wood-oil is made from these seeds, and used for print ink, paint and varnish.