Google 'Asters Yellow' , I don't know if lantana is susceptible, but that is what it looks like to me.
Jim

Agh! I have this same problem and came here to see if I can find out what this is. I'll google asters yellow to see what I come up with. Thanks!

Ok- I think it's definitely Aster Yellows disease, caused by a phytoplasm which is a microscopic thing spread by leafhoppers. The disease affects over 300 plant species, and is in curable. It's most commonly spread from dandelions and plantain weeds. You have to remove the plant and destroy it before it affects other plants in the garden! I've seen pictures of infected carrots, onions, echinacea, vinca, and loads more. I can't find a photo of an infected lantana plant but mine looks like yours, Greenan.

Thanks for the tip, Jim!

Here is a link that might be useful: Wikipedia article on Aster Yellows

Sorry to learn the treatment likely means loss of you plant(s).

Link has photo of lantana with this problem from the Houston Chronicle in '08...

Here is a link that might be useful: Lantana flowers turn green?

This post was edited by bostedo on Wed, Jun 18, 14 at 11:08