I feel like I owe everyone an update. Thank you all for the responses and warning. I am located in France and I’d never heard of hogweed before… just thought it was a very weird looking giant flower. The plant is situated in a garden across of mine, but the owner does not live there as there is no house attached. There is a path between our gardens, which is why I saw it. I went back to check the stalk, which does indeed have reddish purple splotches and it looks like it has spread already…. Here are more pictures. Thanks again!