[1] It was formerly widely treated as a subspecies of the European species Equisetum telmateia, and still is by some authorities.

The range extends from southeastern Alaska and western British Columbia south to California, mainly in coastal regions,[2] but also inland to Idaho.

The fertile stems are produced in early spring before the sterile shoots, growing to 17–45 cm (6.7–17.7 in) tall with an apical spore-bearing strobilus, and no side branches.

Unlike the similar E. telmateia, the main stems are green and photosynthetic.

[2][3] It is found in damp places, spring fens and seepage lines.