Hi. I never like to see a post go unanswered, even when I don't know the answer! It sort of looks like some of the things that grow under the bird-feeder. If you post another pic when it
flowers, we (someone else) will be sure to be able to identify it. I love it when people don't pull up things that grow on their own. I have 2 really beautiful Datura Stramonium in front of the house, no idea how/why they got there, and a 14 foot (at least) poke
weed at the corner where the fence meets the house. I can't wait to see who comes to eat the berries when they ripen. I look forward to your next pic!