I strongly suggest going with local seed for native and naturalized wildflowers. Check out the link below. It seems we can finally get Florida produced wildflower seeds. I've heard there are other sources too, but I haven't found them yet.

In the past I've tried Texas wildflower seeds. They were the same species--often a native species--but a different ecotype, and they did not do well for me. The naturalized phlox on the side of the road did much better than the phlox in my garden. The same was true of Indian blanket and others. The one exception was tropical sage. The Texas variety did fine and still pops up everywhere.

Poppies, cornflowers, candytuft, and toadflax are also good candidates for direct fall sowing here.

Zinnas, yellow cosmos, gomphrenas, tithonias, wild madagascar periwinkles are easy reseeders for spring sowing.

Bill

Here is a link that might be useful: Florida Wildflowers

Thanks Bill. Great info.
Are you saying that the Zinnas, yellow cosmos, gomphrenas, tithonias, wild madagascar periwinkles will reseed in the spring from seed dropped the previous season? I get alot of vinca reseeding. I would like to get some cora vincas and drop the seed in the fall along with others you mentioned.
Instead of collecting the seed and putting them out in the spring I would rather put them out in the fall.
Another interesting plant is:(from the ufl trial site).
"Helenium
(Helenium amarum)
This crop is listed as a Florida native and has not been evaluated in our best-of-class trials before.
Gold class. ÂDakota Gold was uncontested best-of-class with outstanding overall performance. Foliage was very full and uniform, and flowers were numerous and evenly distributed over the plant. The plant centers opened up very slightly late in June. This plantÂs bright green foliage was unique compared to any crops weÂve seen thus far, and should make this plant a very striking focal point in the landscape."
That is from the University of Florida test garden site (link below). The seeds are super expensive. From geoseed the price is 100 seeds $13.15. And Geoseed is the least expensive. Alot of sites like it. Not sure I like it. But if I spend $13.15 I will learn to like it. Yahoo and Google have good pictures of it under images.
Bob

Here is a link that might be useful: UFL