Pale Smartweed; Knotweed
Polygonum lapathifolium /Smartweed Family
(INN) Rank 3
There are no fringes on the leaf sheaths of this plant, one of the identifying factors of Smartweeds. It is a common yard weed. I found this one growing on the edge of my yard in Oak Ridge in August. Close-up of flowers follows.
Where seen: Oak Ridge Greenways, Great Smoky Mountains NP, Warriors' Path SP