I am a forestry student and an avid fisherman from the King of Prussia area, Pennsylvania. I've encountered a certain vine a few times along riversides in the area, most notably the Schuylkill river. I don't have any pictures yet, but the best description I can provide is that the leaves are oppositely arranged, have a palmate shape (but are simple) with an angular stalk and is completely covered with tiny downward point hook-like thorns. It's painful to walk through and completely covers certain areas, leading me to believe it's non-native. I've seen it growing in the same areas as Japanese knotweed. Any help identifying this plant would be greatly appreciated! Thank you!
