(Oxypolis rigidior)
Oxypolis rigidior, also known as cowbane, pig-potato, or stiff cowbane, is a poisonous species of flowering plant in the celery, carrot, or parsley family native to eastern North America. Cowbane is a perennial wildflower found in wet habitats. Oxypolis rigidior is 2-6 foot tall perennial herb of eastern North America. Its leaves are compound, odd-pinnate with 7-11 leaflets, and have variable shape. Umbels of 3 mm white flowers appear August to October. Flat fruits with conspicuous "wings" appear October through November.