スイカズラ科ニワトコ属の落葉低木で、学名は Sambucus racemosa ssp. sieboldiana (syn. Sambucus sieboldiana)。英名は Japanese elderberry。
The Japanese elderberry (Sambucus racemosa ssp. sieboldiana) belongs to Caprifoliaceae (the Honeysuckle family). It is a small deciduous tree that is distributed from Honshu, Shikoku and Kyushu of Japan, as well as the Korean Peninsula. This tree grows in outskirts of woods and can reach about 5 m in height. The leaves are imparipinnate. The numerous pale yellowish white flowers come in the panicles from April to May. The fruits ripen dark red in the Bai-u (rainy season). The burned ash of the twigs had been used for poulitices of fracture in Japan. The Japanese name "Niwa-toko" comes from its use as a perch for chickens. Another name in Japan, "Sekkotsu-boku" (grafted bone tree) comes from the fact that blackened twigs were used as a poultice for broken bones.