Well, I checked the Florida Atlas of Vascular Plants to see what grew in my area. They don't have P. debilis listed anywhere in the state. I do have P. tenellus and P. urinaria in my area. I looked at the photos and based on the way the seedpods sit on the plant, I tend to think it's P. urinaria. Those seedpods are right against the stem whereas P. tenellus looks like the seedpods have their own little stems that hold them off of the main stem. Now, I have to go do some caterpillar research! Although moths tend to eat a lot of things so I'll probably have to wait until these guys emerge from their cocoon to know what they are. Thanks everyone! ATP is such a great site!