Collecting Wild Plants?

Hey folks! I live in SW Florida and I've found a few neat plants in the local river. I dug a few up and am trying to grow them in an outside aquarium with dirt/rocks and sunlight just to make sure I can keep them alive. And frankly because I'm afraid of putting them in my aquariums.

I couldn't identify them for the life of me.Of the survivers, one is a lily or something, which I know have an awful reputation in the aquarium, and the other looks like some sort of underwater "lettuce".

These plants, having melted away, have regrown in captivity - giving me a measure of confidence that I can at least keep them alive. They have been in an outdoors aquarium for approximately one month now. The water's a little nasty, and stagnant, but they seem to be doing very well.

I've heard about parasites and chemicals and such... what's common procedure here? I've heard whisperings about dipping the plants in bleach, but remain skeptical of allowing any living thing to touch a bleach solution, and doubly skeptical about putting the plants back into water with fish in it! . Has anyone here done this personally?

Also, does anyone have thoughts about pollution? I mean, as far as I know, there's no real way to tell what's actually in the local water supply...