It's one of the native FL wild lettuces. Kate, you will have several varieties. You will most likely have this one too. Grassleaf Lettuce (Lactuca graminifolia)
We will have a lot of the same things growing wild. You can check my plant list anytime to find out what you have. https://garden.org/lists/view/...
I am a strong believer in the simple fact is that what matters in this life is how we treat others. I think that's what living is all about. Not what I've done in my life but how I've treated others. ~~ Sharon Brown