The bright green stems of this horsetail are quite attractive. Intermediate Horestail is a sterile hybrid of Equistem hyemale var. affine (Scouring Rush) and Equisetum laevigatum (Smooth Horsetail). Its physical appearance is intermediate between these two species and it can be difficult to distinguish this hybrid from its parents. Generally, Scouring Rush is a slightly larger horsetail with stems that are 2–3½' long and about ½" across; these stems are evergreen throughout and their joints are conspicuously grey. Smooth Horsetail has stems that are more narrow (about ¼" across) and entirely deciduous; the stems of this horsetail are often bunched together in loose clusters, while the stems of Intermediate Horsetail and Scouring Rush are more evenly spaced (a consequence of their long rhizomes). For a sterile hybrid, Intermediate Horsetail is surprisingly common within the state.