Tropicals & Tender Perennials: EE questions, 1 by Paintedlady

Paintedlady wrote:
Since these turned out to be such fun plants to grow I bought another EE at a nursery. It was called Voodoo, but I can't find any EE anywhere on the internet with that name. Is there such a plant?
That's the one in the photo.
While surfing around, I realized there are several different EE's, but I couldn't find any explanation as to what the difference is between Colocasia, Alacasia, X...somethingoranother, and there was one more. Is there a web page out there that explains the difference? Or does anyone of y'all experts know?

Kris