Equisetum hiemale var. Suksdorfi A. A. Eaton, Fern. Bull. 11: no. 1903.
Somewhat similar to the variety affinis but has whorled branches from the upper nodes, which are spike-bearing simultaneously with the central stem; Mr. Eaton described it as with the anatomy of E. hiemale but material distributed by him shows the green parenchyma cut by the vallecular bast which, with the branching habit, indicates a tendency toward H. laevigata, while the rosulae in the groove show a trend toward H. hyemalis var. californica. Collected by W. N. Suksdorf, September 3, 1902, at Bingen, Washington.