Equisetum hyemale var. praealtum (Rafinesque) Clute

Equisetum hyemale var. praealtum (Rafinesque) Clute is a synonym sensu Christenhusz et al., 2019 of:

Equisetum hyemale subsp. affine (Engelmann) Calder & Roy L. Taylor, an accepted subspecies name sensu FNA Ed. Comm., 1993.