"Stachys floridana" is classified by most every one I could find as a noxious weed, but I could not find much about it from a Florida source. It is called "rattlesnake weed" because of the shape of the roots and it spreads by the roots, rhizomes, and seeds. Aside from poisons most places recommend good thick mulches to keep top growth from getting sun.

Here is a link that might be useful: Clemson U. Fact sheet

The root of Stachys Floridana aka Florida Betony is delicious. My solution is not poison it but eat it. The cultivated version-- stachys affinis aka Crosne-- is expensive in gourmet restaurants. It does spead like wild, but then again it is wild and I eat it all the time raw. I've never tried it cooked because I eat it long before I get to the stove.