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Northern Prairie Wildlife Research Center

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Aquatic and Wetland Vascular Plants of the Northern Great Plains

1. Equisetaceae, the Horsetail Family

1. Equisetum L. -- Horsetail, scouring rush

3. Equisetum hyemale L. -- Common scouring rush


Stems alike, erect, evergreen, viable for probably 2 or 3 years, simple or producing few, short, erect branches from the upper nodes, 2-12(15) dm tall, mostly 18- to 40-ridged, the ridges roughened with silica deposits; central cavity at least 3/4 the stem diameter; main stem sheaths shorter or not much longer than broad, 5-15 mm long, with both an apical and basal dark band, the teeth dark brown to black, connate by the scarious margins toward the base, 2-4 mm long, deciduous or persistent. Cones terminal on the main stem or produced on the short branches after the first year, sharp-pointed, sessile to short-stalked, eventually deciduous, appearing Jun--Sep. Often in dense colonies in seepage areas, wet meadows, ditches and along shores and stream banks, usually where sandy or gravelly; occasional; (Circumboreal, in N.Amer. s to FL, TX and CA). E. praealtum Raf.

North American representatives of E. hyemale belong to var. affine (Engelm.) A. A. Eat. (See also the discussion of E. X ferrissii Clute under E. laevigatum.)

GIF-Equisetum hyemale L.
GIF- Distribution Map

Map key

Equisetum hyemale, cone-bearing stem.  

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