About Equisetum variegatum Schleich. ex F.Weber & D.Mohr
Equisetum variegatum Schleich. ex F.Weber & D.Mohr is a variable species that hosts multiple ecotypes, some of which are recognized as distinct subspecies. Its stems typically reach up to 40 cm in height, and may occasionally grow as tall as 80 cm, though many stems are much smaller. Different forms of the species vary in growth habit: some produce prostrate stems that creep along the ground, while others grow more erect. The slender stems are dark blue-green, rough to the touch, and may be unbranched, or develop branches from their base. Each stem node is covered by a sheath marked with a black band; the sheath bears dark teeth with white edges. A small 3–4 mm wide cone grows at the tip of each stem. This cone is usually green, with a bluntly pointed black tip. This species has a circumpolar distribution across the northern hemisphere, found in northern Europe, Asia, and North America, including Greenland, Iceland, and the Faroe Islands. Its range extends south to the Pyrenees and Apennines in Europe, Mongolia and Japan in Asia, and Connecticut, Wisconsin, and Oregon in North America. It favors open, lime-rich sites that often flood in winter, and grows in dune slacks, mountain flushes, and along the banks of lakes, rivers, and canals.
