does anyone know the name of an asian plant with arrow-shaped leaves and tuberous roots?

Question

it's a cross word clue, eight letters long and all the letters we have now are (?) c (?) m(?) o(?) y

Answer 1

It is scammony.

See the illustratiion below:

Answer 2

If it's large, it could be an alocasia, that seems rather likely.

There are others in the aroid family like anthuriums (possibly) or typhonodorum (rather rare).

If you care to send a picture to [e-mail], I may be able to identify it for you.

Best!