The Lesser celandine (Ranunculus ficaria) belongs to Ranunculaceae (the Buttercup family). It is a perennial herb that is native to the Mediterranean Basin of Europe and Asia Minor. This herb grows in montane forests and edges, and it can reach 10-15 cm in height. It prefers cool environment and wet shade shade places. It comes into leaves in early spring and blooms yellow or white flowers. The terrestrials are blighted in early summer and diapause during the summer. The Japanese name is derived from the similarity of its flowers and leaves to the Japanese "ryukinka" (Marsh marigold). The 3rd photo is a purple-leaved variety.