Equisetum laevigatum is a rush-like perennial that rises from an underground rootstock structure. Normally the plant dies back over the winter, but some populations in the southwestern USA have individuals that can overwinter. The plant manifests jointed rough stems which are closed at the joints. The stem roughness are a result of inclusions of silica. Each stem exhibits longitudinal grooves that run vertically. Each joint has a sheath which is a minute pointed leaf-like structure. The species usually occurs along moist drainages in sandy and gravelly substrates.

The narrow green stems can attain heights ranging from 30 to 150 centimeters. The stems are generally unbranched and are capped with rounded cone-shaped sporangia. Stomata occur in single lines; moreover, the spherical spores of this species are green.