"Shirobana-hansho-zuru" (Clematis williamsii) belongs to Ranunculaceae (the Buttercup family). It is a deciduous shrub that is distributed westward from the Pacific Ocean Side of southern Kanto district to Kinki district of Honshu, Shikoku and Kyushu in Japan. This shrub grows mainly in forest edges on calcareous places, and can reach about 5 m long. The leaves are trifoliate with intermediate trilobate, ovate leaflets. The peduncles are borne at the axils of new branches, the pale yellowish green tinged, white and broad campanulate flowers bloom from April to May. The corolla has four petaloid sepals.