Japanese name: オニドコロ（鬼野老） Scientific name:Dioscorea tokoro
[Overview]
A climbing perennial found in hills and fields.
The rhizome is thickened and creeps horizontally.
The vine is hairless.
Leaves are simple and alternate, round-heart-shaped to triangular-heart-shaped, 5–12 cm in both length and width, with a pointed tip.
The petiole is 3–7 cm long.
It is dioecious.
Male inflorescences stand erect, and female inflorescences hang down.
Both male and female flowers are yellowish green, with 6 tepals that open flat.
Male flowers have short stalks, and all 6 stamens are complete and fertile.
Female flowers are stalkless.
The fruit is an obovate-elliptic capsule 15–18 mm long and 14 mm wide, with 3 wings.
The seeds are elliptic, about 4–5 mm long, with a wing on one side.
[Uses]
It is poisonous, and the rhizome was used as a fish poison.
In the past, the rhizome was used as a New Year decoration.
The rhizome is bitter and is not edible.
