I think your plant is Colocasia escuelenta. The plain green form, sometimes marketed in the past as 'Green Goddess'. Colocasia and alocasia have pretty big differences in hardiness. Colocasia are much more likely to return in a cooler climate than ALocasia.
You can tell it is a colocasia because the petiolar attachment to the leaf is positioned in such a way that the leaves 'hang' point downward.
In most ALocasia the attachment makes the leaves point UP.
I have this plant all over my yard, its nice to see it somewhere else where it can be kept contained. Here in FL it is considered a noxious weed (the green form is) and they ask homeowners not to plant it. It gets into natural waterways and causes a lot of trouble. They don't sell this plant here to my knowledge, but they do sell the more decorative Colocasia escuelentas like Mojito, Elepaio, Midori, Lemon Lime etc.
You can also grow this in the warm months as a pond plant.
