Equisetum hyemale (commonly known as rough horsetail, scouring rush, scouringrush horsetail and, in South Africa, as snake grass) is a perennial herb in the fern Phylum Pteridophyta. It is a native plant throughout the Holarctic Kingdom, found in North America, Europe, and northern Asia.Equisetum hyemale has vertical jointed reed-like stalks of medium to dark green. The hollow stems are up to 3 feet (0.91 m) in height. The stems are seldom branched. The stems themselves have conspicuous ridges, which are impregnated with silica. This makes the ridges feel rough and harsh. The tiny leaves are joined together around the stem, forming a narrow black-green band or sheath at each joint. Like other ferns and their relatives, the plant reproduces by spores and does not produce flowers or seeds. The stems are generally deciduous in cold climates, and remain during winter in warmer climates. It forms dense spreading colonies, in full to partial sun.