ノウゼンカズラ科キササゲ属の落葉高木で、学名は Catalpa ovate。英名は Chinese catalpa。
The Chinese catalpa (Catalpa ovate) belongs to Bignoniaceae (the Trumpet creeper family). It is a tall deciduous tree that is native to China. It was introduced into Japan in the ancient days, nowadays it is naturalized in stream banks and edge of lakes, and can reach 5-15 m in height. The leaves are broad-ovate, having three to five lobes, and arranged in opposite or three whorled. The edges of leaf blades are entire. The panicles are borne on the terminal branches, and the yellowish-white flowers bloom in June and July. The corolla is funnel-shaped, and quintuple-lobate at the tips with dark purple mottles on the inner surface. The fruits are capsules, 30-40 cm long. They are used a herbal medicine for diuretic agent. The timbers are light, and used for Japanese wooden footgears and equipments. In Chinese, it is called "梓" (zi).