"Mizu-otogiri" (Triadenum japonicum) belongs to the family Clusiaceae. It is a perennial herb that is native to various parts of Japan, the Korean Peninsula, China, Amur and Ussuri. This herb grows in ponds, bogs or marshes and can reach 30-80 cm in height. The leaves are oblong and opposite with bright spots on the surface. They turn bright red in fall. The pale rose-pink flowers about 1 cm across come in August through September. They are open from afternoon to evening.