Just checking these forums again today and thought I should clarify that the effect I was referring to was the UV sensitization. The phytophotodermatitis can leave visible marks for weeks, months, and even years in extreme cases. I had a small burn on my hand that was probably caused by this plant and it remained darkly pigmented for about 6 months.

Wow - that really is hard to make out! Google up Clerodendrum bungeii and see what you think. But a picture in which the plants are visible would be good ;)

Lantana camara

The only Acalypha with that appearance in your area is A. rhomboidea. A. virginica is similar, but usually has shorter petioles and ranges further to the south.