You're on the wrong page, Clusiana. Polygonum cuspidatum is a synonym of Fallopia japonica var. japonica.

Thank you Zuzu.
It is far too hot here. My neurones are melting.
Arum is not a genus right. I was not in the mood so I put anything. Thanks for your help.
Never heard of Fallopia before and never saw it as a synonym. You taught me something today. Thank you.
C.

Actually, Clusiana, I hope you didn't misunderstand my earlier comment. Arum is a genus. It just wasn't the genus in that particular case.

OK Zuzu. Thank you
C.