Cimicifuga racemosa

Just down Federal Twist Road is a community of Cimicifuga racemosa . I first saw it last summer, but this year it appears to have grown to over 20 well sized plants. They're at the front of a property someone is building on, but construction has been stopped for almost a year, and the new house is several hundred feet back. I'm hoping the plants will remain undisturbed.

Compared to the yellow green of the blackberry foliage in the picture below, the cimicifuga appears quite dark. Is this a natural genetic variation?

(I know it's been renamed Actea, but I haven't made that adjustment yet.)