Marsh horsetail
Equisetum palustre

E. palustre is a perennial cryptophyte, growing between 10 to 50 centimeters (4" to 20"), in rare cases up to one meter (3'). Its fertile shoots, which carry ears, are evergreen and shaped like the sterile shoots. The rough, furrowed stem is one to three mm in diameter with usually eight to ten ribs, in rare cases, four to 12. It contains whorled branches.