Oriental bittersweet climbing onto a white pine. It was
introduced to the US supposedly in 1860 as an ornamental vine "chiefly
grown for handsome yellow fruit opening at maturity and disclosing the crimson
seed" (Alfred Rehder). 150 years later it is known as the most horrible
weed of natural habitats capable of killing entire forests of mature trees.
Once it becomes established, it is extremely tough to eradicate.