This plant was found growing in Western NC mountains. Woods are largely oak with lots of heath understory ( rhodie, azalea etc). Creek is nearby and the area often gets a lot of water. Neighbor had a large tract cut down so he didn't have to pay taxes and what is growing back is largely Kalmia and blackberries. This plant is growing there and I would say it is vigorous so am guessing it is invasive? I think I ruled out russian and autumn olive as the leaf margins are not smooth. Undersides of leaves are whitish and pics show dead flower stalk. Thanks for your input! PS stem is square.
EEK! Buddleia! That's it isn't it? In the middle of what was a small patch of high quality woodland. Amazing to think this patch of woods was once home to Cypripedium acaule and trilliums...wish they'd make this kind of habitat destruction illegal.