Hello!

I think you mean Arum Lily, also referred to as the Calla lily or Zantedeschia aethiopica. You can find several photos online if you haven't seen one b4. It is not rare.

There's also another plant in the same family that's also called Arum Lily. This is Dracunculus vulgaris. I has pretty tropical leaves with an enormous flower, but with a foul smell!!

Cheers,

Riz