Photo 2

Photo 3

I couldn't be sure which one of the possibilities of species, but it sure looks like one of the water hemlocks.

That is the spotted water hemlock, Cicuta maculata.

Researching Cicuta maculata on the web has led to a lot of confusion. One site suggests that it is a synonym for Cicuta douglasii, but that seems to be incorrect information.
http://science.halleyhosting.com/nature/gorge/5petal/pars/cicuta/waterhem.htm

How to tell the difference between the two? I've also found hemlock with parsley-like leaves referred to as spotted water hemlock. And that leads to another question: Why is it called "spotted"?

With few exceptions, most of what has been identified as C. douglasii is not genetically distinct from C. maculata. If you are interested in the work done on this

http://www.life.illinois.edu/downie/Cicuta.pdf

It is called spotted water hemlock (maculata means spotted) because the stems sometimes have purple spots. The introduced poison hemlock (Conium maculatum) also has purple spotted stems and more finely divided leaves. There is a plant called hemlock parsley (Conioselinum chinense) that grows in fens that is superficially similiar. The bulblet-bearing water hemlock (Cicuta bulbifera) is a much more delicate plant compared to the rest of these.

lycopus, that is great information and very much appreciated. Thank you!

I guess someone should mention that any part of water hemlock can kill you dead. It's especially toxic to grazing livestock and may be the most poisonous plant in the U.S. It ranges south into Florida but not as far south as where I live in Homestead.