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DescriptionThis native perennial plant produces fertile and infertile shoots that are deciduous. Each fertile shoot is unbranched and about 4-6" tall. It has a central stalk that is light brown to brown and about ¼" across in diameter. This stalk terminates in a spore-bearing cone up to 1" long; the cone is oblongoid in shape and rounded at the top. The surface of the cone is mostly brown, but it is covered with spore-bearing tubercles that have black and white markings. The fertile shoots develop during mid-spring, but soon wither away after the cones have released their spores. The infertile (or vegetative) shoots have a very different appearance. They develop during late spring and persist until the fall. The infertile shoots are ½2' tall; they have whorls of branchlets along at least the upper half of their stems. The stems and branchlets of these shoots are slender and green. Each central stem consists of several joints; at the apex of each joint (except the uppermost), there is a short sheath with 3-4 teeth along its upper rim. This sheath is appressed to slightly spreading and green to brown. The base of the next joint develops from this sheath. Each joint is terete with 10-14 ridges along its length; sometimes there are more or fewer ridges. Initially, the branchlets are similar to the central stems, except they are much smaller in size. Later, they become almost as long as the stems. At this stage, the infertile shoots resemble small conifers because of the long needle-like branchlets. The branchlets have joints with sheaths like the stems, but there are only 3-4 teeth along the upper rim of each sheath. Usually, these branchlets are unbranched, but sometimes they produce secondary branchlets. An infertile shoot may produce a small infertile cone at its apex, but this is very unusual. Both the stems and branchlets of Common Horsetail are mostly solid. The root system consists of long rhizomes and secondary fibrous roots. This plant often forms colonies.