The Buttercup winter hazel (Corylopsis pauciflora) belongs to Hamamelidaceae (the Witch hazel family). It is a small deciduous tree that is distributed to the Japan Sea Side of Honshu, westward from Ishikawa prefecture to Hyogo prefecture of Japan and Taiwan. This tree grows in infertile rocky places and can reach 1-3 m in height. The leaves are irregular ovate to broad ovate and alternate. The drooping pale yellow flowers come in March to April before foliation. In Taiwanese Chinese, it is called "小葉瑞木".