Posted: 28/08/2014 at 16:35
It's either Arum maculatum if it's got green leaves with or without black spots. That's Lords and Ladies, Jack in the Pulpit, for 2 common names.
Or if it's got rather nice variegated leaves it's Arum italicum .
My guess is the former if you didn't put it there.
What I call Arum lily is Zantedeschia which these are not.
But with common names anything might be true