Well, the leaves are too big to be that eupatorium, and they're not lance-y enough to be ruellia. Also, I've never seen ruellia growing here. I tried sowing some seed in a flat last year but never got sprouts.
Name: greene Savannah, GA (Sunset 28) (Zone 8b) I have no use for internet bullies!
I was basing my guess for Rudbeckia on the vein pattern in the leaves. The one Rudbeckia with darker stems I can think of is R. triloba but my eyes aren't good enough to see any tri-lobed leaves in your photos, so I made a generic Rudbeckia guess.
Sunset Zone 28, AHS Heat Zone 9, USDA zone 8b~"Leaf of Faith"