elephant ears question

As far as I know, colocasias are all tropical related to caladiums. They are not cold tolerant and must be lifted in areas where there is frost. I have never seen any wild elephant ears in the Midwest. Are you confusing these with daylilies, sometimes called "ditch lilies?"

There are no "Elephant Ears" that grow like ditch weeds around Chicago. None of the Colocasia are cold hardy.

Could you be alluding to "Skunk Cabbage"?

or perhaps Sagittaria?

I live 25 miles outside Chicago and can show you Elephant Ears in hedgerows, in roadside ditches, and in the scrub at the back of my lot. They're found in vacant lots all over the city  -   i grew up there.

They grow about the size of established rhubarb clumps and will produce a burdock like seed pod if left unmolested.  The leaves are even larger than rhubarb and could never be mistaken for tiger lilies.

Don't know anyone who cultivates them as ornamentals tho. Mostly  -  they get rooted out on sight.        

You have just described plants of burdock, babe.

How come "Elephant Ears" are supposed to be poisonous, and taro (Colocasia esculenta) is a food crop?

The foliage and tubers contains oxalates that will decompose when they are thoroughly cooked.

burdock- that's it