Oxypolis rigidior, known as cowbane, common water dropwort,[1] stiff cowbane,[2] pig-potato,[3] and Cherokee swamp potato,[4] is a species of flowering plant in the carrot family native to eastern North America.

[5][6][7] Oxypolis rigidior has been reported as being poisonous to some mammals, but it is also considered edible and safe by some authors.

Oxypolis rigidior is 2–6 foot tall perennial herb of eastern North America.

[7] Both the roots and top parts have been reported as poisonous to mammals including cattle.

He also warns that the plant should be gathered with “great caution” due to its resemblance to water hemlock.