I'll guess somewhere between 50 and 100 depending on how you count the heads on the sides of the main heads. Personally I'm not convinced there are that many types of duncans. It was clearly a green tissue branching Duncan when I got it, but heads cut from it, and even the main colony grow non branching now. If the base tissue gets light it turns green. If it is shaded by heads it turns tan. Feed a lot and you get a ton of heads. Don't feed much and less heads makes it look like it is branching.
