Plant 1 No comments. Plant 2 Tallness reminds me of bushy bluestem (Andropogon glomeratus (Walt.) B.S.P.). The white hairs, which are attached to the seeds, are called the pappi? Plant 3 Flowers remind me of hempvine (Mikania Willd.), identified in a previous thread. Plant 4 Looks like eastern silver aster (Symphyotrichum concolor (L.) Nesom). Came across it while browsing through species of aster (Symphyotrichum Nees).
#1-2 reminds me of [FONT=arial,sans-serif][SIZE=-1]Chrysothamnus, but I don't believe you have those in Florida. [/SIZE][/FONT]
Most likely one of the species of these genera. Both look quite similar. Still looking through them. Symphyotrichum (aster) of the family Asteraceae (aster family)? That would be my guess. Yes, this looks to be the exact plant. :) I agree with little bluestem (Schizachyrium); specifically, it's probably little bluestem (Schizachyrium scoparium).