The Japanese cordwood (sophora japonica L.) is a deciduous tree that can grow up to 30 metres high. During the flowering season in summer, the tree is adorned with numerous small white flowers. It is also called honey tree, pearl cord tree or Japanese pagoda tree and grows in areas of Japan, China and Korea. The Japanese string tree contains the substance rutin. It is a yellowish powder that is produced by some plants as a pigment to protect against UV radiation.