I'm looking for an ID for this plant. I live near White Clay Creek SP, and this plant has taken over my mostly wooded yard. The leafy part of the plant is ~50-60cm tall, with the flowered spike extending another ~30cm. The leaves are alternate, and the stem has nodes like a grass. It has fairly shallow roots, but breaks at the nodes when I try to pull it. I can send additional photos, if needed. The closest I can find in my books is Enchanters Nightshade, but that has opposite leaves and this has alternate leaves. Thanks!
New Castle County Delaware
This is likely Japanese knotweed, polygonum cuspidatum. It is an invasive plant difficult to control once established. You can read more about it by scrolling down to fact sheet #4 in this invasive plant list. https://nccde.org/DocumentCenter/View/556/Delaware-Invasive-Plants-List?bidId=