At this time of year, all across the The South, the chinaberries (Melia azedarach) are ripening. The fruits of this invasive tree species are toxic but some birds eat them anyway, eventually pooping out the undigested seeds. These often germinate to form linear mini-forests beneath the birds' utility line roosts.
From a distance the camphor tree is a handsome species but it has a number of problems and should not be cultivated in the US. It produces large crops of seeds - the reason it is "invading and disrupting native plant communities in Florida."
Tung trees were once grown commercially in parts of the Deep South. Tung oil, extracted from the "nuts", was once an important industrial commodity that lost its importance with the invention of plastics.
This pretty little tree became an invasive pest in many warm-winter climates where it was once planted as an ornamental. The leaves become very colorful in autumn but this a noxious weed in most places and should not be planted.
At this time of year, even North Florida will get a touch of autumn color from the the leaves of several native deciduous species. In my yard the American persimmon trees can be depended on for an impressive seasonal foliage display in red, yellow and orange.
More trees with colorful autumn leaves:
black cherry (Prunus serotina)
Carolina buckthorn (Rhamnus caroliniana)
Chinese elm (Ulmus parvifolia)
chinkapin oak(Quercus muehlenbergii)
cornelian cherry (Cornus mas)
Kentucky coffee tree (Gymnocladus dioicus)
northern catalpa tree (Catalpa speciosa)
northern red oak (Quercus rubra)
pond cypress (Taxodium ascendens)
shiny sumac (Rhus copallinum)
Carolina silverbells (Halesia spp.)
Maintenance people like ginkgo trees because the golden leaves tend to drop from the tree all at the same time!
The littleleaf linden (Tilia cordata) is a durable shade tree noted for fragrant spring flowers, showy autumn foliage and adaptability to urban conditions.
The spiny fruits are a nuisance but there sterile sweetgum (Liquidambar styraciflua) varieties are available that don't produce annoying dingleballs. Sweetgum grows well in moist soils and produces impressive colorful fall foliage displays.
Fall Foliage Plants
Browse Floridata's Fall Foliage Plant List for more species whose leaves turn in autumn.
Eranthis hyemalis is among the earliest bloomers, sometimes their jewel-like flowers appear while snow is still on the ground!
More spring-flowering bulbs that are planted in autumn (now!):
crocus (Crocus spp.)
daffodil (Narcissus spp.)
grape hyacinth (Muscari spp.)
hyacinth (Hyacinthus orientalis)
snowdrops (Galanthus nivalis)
tulip (Tulipa spp.)
winter aconite (Eranthis hyemalis)