The "Sarasa-doudan" (Enkianthus campanulatus) belongs to Ericaceae (the Azalea family). It is a small decidous tree that is distributed to Chugoku district and eastward from Kinki district on Honshu, and Hokkaido in Japan. This tree grows in sunny forest and forest edges and can reach 4-5 m in height. The leaves are obovate, alternate and arranged in whorls at the terminal branches. The drooping racemes are borne on the terminal branches and produce broad campanulate flowers in May to July. The base of collora is pale yellow with rose-pink longitudial stripes, and the tip of collora is pale rose-pink and quintuple-lobate shallowly.