Looks like a leaf fungus, but I couldn't tell you what kind.

It is either a fungal or bacterial leaf blight, but in no way does that indicate it to be a serious problem. All plant species have their own set of pathogens-some serious, some not so much- and especially in a place like Florida, with its never-ending humidity and moisture, it is unrealistic to expect blemish-free foliage on all plants at all times. True, one could embark upon a fungicide spray regimen, but it would be crazily impractical IMO.

So, how bad is this? Just a few splotches as seen here, or are the lesions coalescing into full leaf drop? Foliar disease of plants are rarely serious.

Keep an eye on the spots. If they seem to be spreading I would be concerned. If you are into organic try neem oil otherwise something like Dithane M-45 may help. I went out and had a look at my tree and there were no spots.

Probably not serious. Are you overwatering your tree? When you water, don't wet the leaves and try to water in the morning, not the evening. Wet leaves overnight tend to create spots.

Thanks All who replied.
The plant is newly planted. It, whatever it is, seems to be spreading. I've taken care to not water any part of the plant except the root system since it's been in it's new home.
I'm treating the plant with Fungicide 3. I started a few nights ago. Hopefully, the whole plant won't be zapped by whatever it is.