Green shrimp plant is an Extremely common weed here in Southeast Florida, at least in Palm Beach and Broward counties. You’ve probably been mowing it. I was before I figured out what it was. Then I preserved several areas of it in my yard, and weeded the grass (shh, don’t tell my husband!), but the Malachite Butterflies never came. I’ve heard that they like rotten fruit and wooded areas, but can’t confirm that since I’ve never seen one in person (yet). Finding one is on my very long list of things to do.