Rough Horsetail

Rough Horsetail (Equisetum hyemale), also known as scouring rush, is an evergreen perennial horsetail native to Iceland, Greenland, and central and northern Eurasia, including Kamchatka and Japan. It grows vertical, jointed, hollow stems 30 to 100 centimeters tall with 10 to 30 silica impregnated ridges that feel rough to the touch, from which its common name derives. It forms clonal colonies in consistently moist habitats such as riverbanks, lake shores, ditches and marshes, and its dried stems have traditionally been used in Japan as a polishing material. It was formerly treated as including a North American subspecies now recognized as the separate species Equisetum praealtum.