Japanese Taro (Satoimo)
(Colocasia esculenta)
Closely related to the tropical varieties of taro, this root vegetable is usually grown in irrigated paddies.
It needs to be cooked to destroy calcium oxalate, which is toxic to humans.
Taro is often referred to as Elephant Ear, a name also given to the ornamentals Xanthosoma and Caladium to which it is related.
Colocasia esculenta at Wikipedia