The "Tsukubane-so" (Paris tetraphylla) belongs to Liliaceae (the Lily family). It is a perennial herb that is native to all over Japan and southern Sakhalin. This herb grows in mountain woodlands and can reach 20-40 cm in height. The leaves are elliptic and arranged four whorled at the top of stem. The green flower blooms at the stem apices from May to August. The corolla has only four outer tepals. The globose fruit ripens purplish black.