It does look like Prunus americana, but the description states:
Flower: White, 5 petals, 1 inch across, long filaments, yellow anthers, appear in small clusters in early spring with the leaves.
It could still be correct, but could the flowers come before the leaves?
I went through the Prunus on the USDA site, only those showing in Florida. There's one which is a possibility although it was difficult to find photos of, I got some by searching 'Flatwoods Plum', Prunus umbellata.
It flowers before the leaves, not sure about the leaf shape but they haven't opened fully so it's difficult to say.
http://www.sfrc.ufl.edu/4h/Fla...
Flatwoods plum grows in mixed pine-hardwood forests, hammocks, coastal scrub, and swamps near streams and rivers.
The bark is thin, smooth, red brown to black in color, often becoming rough with age.
Flatwoods plum is a small tree that is generally less than 20' in height. Its crown is usually spreading and form is often crooked. It does not occur in thickets as a large shrub.
Twigs and leaves look close on the USDA ..
http://plants.usda.gov/java/pr...
The bark looks more like the thinner trunk, maybe you could compare it more closely Ginger. If it ever fruits then they could be a good clue too.
http://plants.usda.gov/java/pr...
I got a lot of results from the 'Flatwoods Plum' image search, the older bark is shown on this site ..
http://www.southeasternflora.c...
http://www.google.co.uk/search...
