Question
How many native trees does Florida have and what would one be

Answer
There are approximately 90+ native trees in Florida. There has been many more exotic trees moved into Florida. Here is a web link to these trees. The Florida State Tree is the Sabal Palm, also known as, the Sabal Palmetto, Cabbage Palm, or Palmetto. As a native tree in Florida you'll find it growing wild throughout the state.

http://flame.fl-dof.com/apps/trees.php

One of the most common is the live oak.
http://www.sfrc.ufl.edu/4h/live_oak/liveoak.htm