Taro, aka COLOCASIA has been farmed for eons as food.
http://libweb.hawaii.edu/libdept/scitech/agnic/taro.htmlIt's ALOCASIA species that are poisonous.
How to tell between the 2 plant types?
Alocasia and Colocasia leaves are generally shaped like hearts.
You can see the spot where the stem attaches underneath, usually lighter than the rest of the leaf.
If it is attached at/near the notch, and heart shape pointed upward/upsidedown, it is Alocasia. (*although there are exceptions here too, not all are upright)
If it's attached near the center, or a little off center so the heart shape hangs down, right side up,
it's a Colocasia.
Generally, Colocasia like water, and Alocasia don't. Although there are exceptions.
Whatever, it's not hard to Google a plant the day you buy it, to make sure the tag is correct,
and to be a responsible plant owner. If you're posting here, you have a computer, and can Google any plant you want.
Both plants can be grown, and grow best planted right in the ground, in well drained soil that isn't allowed to dry out.
They are extremely heavy feeders, so keeping them well mulched with compost and/or leaf mold is a very good idea.
Even better, sprinkle a half cup of Osmocote (or Multicote) around the base of each plant before you mulch.
Try planting them both ways, crammed into little pots and then sunk in the pond, and then plant one in your garden some place where it won't dry out, where you can water it often, and where there is some run off from a roof or AC unit.
Once you see how well they grow in the ground, you won't wanna grow them little strugfgling pathetic things in a pond anymore.
They just need more room than most pots provide, and more nourishment than the pots can hold.
http://www.hardytropicals.co.uk/Aroids/If you want to grow it in a pond, get Colocasia, not Alocasia.