Arisaema ringens

Arisaema ringens, the Japanese cobra lily (a name it shares with Arisaema sikokianum), is a species of flowering plant in the family Araceae, native to the Zhoushan Islands of China, Taiwan, South Korea, central Japan, and the Ryukyu Islands. A tuberous geophyte reaching 45 cm, in the wild they are found at low elevations in forests. A dioecious species, it is pollinated by flies. In the garden it needs moist, humus-rich soil, and is hardy in USDA zones 6 through 9.