Surprise, it's an Iris

So I got this free iris from a vendor at the Zoo event Bloomin' Crazy about 4 years ago. I stuck it in a pot with some flat leaf parsley that has since died.

The other day, Ben says, "Your big white flower is blooming." WHAT?

I look outside before I say he's crazy and that iris is blooming! One stalk with 3 flowers. I didn't even notice it throwing out a spike.