Equisetum scirpoides (dwarf scouring rush, dwarf horsetail) Michx., Fl. Bor.-Amer. 2: 281 (1803). 2 n = 216. The smallest of the currently occurring representatives of the genus Equisetum (horsetail). It occurs mainly in the area of the Arctic Circle in Alaska for the Indians and Greenland, Idaho, Montana, South Dakota, Minnesota, Iowa, Illinois, New York and New England. Creates a compact and dense clumps. Reaches a maximum height of about 30 cm. The assimilation and generative shoots are identical and grow together. The leaves reduced to a black sheath around the stem. The stems are green, unbranched, thick and about 1 mm with six ribs. The generative shoots with small cones dying after sowing the spores. The nodes occur at approximately 1 – 3 cm. The leaves are very small to about 1 mm,