"Hana-yu" (Citrus hanayu) belongs to Rutaceae (the Citrus family). It is a small evergreen tree that is probably native to Japan, however, the truth is unknown. This tree grows about 3 m in height. The leaves are elliptic, smaller than the Yuzu (Citrus junos), and have small, inconspicuous petiole wings. The scented white flowers bloom from March to May. The fruits are hesperidiums, and ripen yellow in September to December. The skin of the friut is rough and uneven. The flowers and fruits are used as a flavouring in Japanese cuisine. Its scent of fruit skin is a little bit weaker than Yuzu's one.