Northern Prairie Wildlife Research Center
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.)
Previous Species -- Equisetum fluviatile L.
-- Water horsetail
Return to Family -- Equisetaceae - The Horsetail
Next Species -- Equisetum laevigatum A. Br.
-- Smooth scouring rush