Sterile Stems: to 45 cm, mostly erect but sometimes partly decumbent, green; slightly roughened surface with 12 or more ridges
Nodes: ~ 3 cm apart; sheathes widening upward, about as long as wide, light brown at base, dark brown at top; teeth with dark centers and distinct white margins, deciduous
Branches: horizontal horizontal, thin and delicate; lowest branch usually shorter than upper branches; 3 sided; sheathes light brown at base, dark brown at top; 3-4 sharp-tipped black teeth; first internode of branch is same length or up to twice as long as the sheath of the node from which it arises except in the upper branches where it may be slightly longer.
Cavity: central cavity small, ~ 1/5 to 1/4 diameter of the stem; vallecular canals large
Fertile Stem: to 40 cm, erect, straw-colored, without branches; after strobilus disappears becomes green and branched appearing much like sterile stem; in our area rarely produced
Cone: 2-3 cm long, on long stem, blunt tipped
Habitat: rich, moist soils along brooks; moist slopes; damp woodlands
Similar Species: most likely to be confused with Equisetum arvense, Field Horsetail. Many characters overlap somewhat: (1) E. arvense usually has stouter and rougher branches, but when growing in the shade they may be somewhat thinner; (2) E. arvense usually has more upswept branches, but when growing in the shade they may be more horizontal; (3) the first internode of the lateral branches is usually much longer in E. arvense than in E. pratense. Although at first it may seem difficult to differentiate between these species, if one uses all of the characters it is usually easy to determine the identity of a specimen.
Note: after a killing frost in the autumn E. pratense bleaches out into a ghostly white while E. arvense becomes a dirty gray-brown