Equisetum variegatum var. alaskanum A. A. Eaton, Fern Bull. 12:39. 1904.
Somewhat similar to the last variety but larger, yet with a relatively smaller centrum, awns deciduous, arid anatomy much like that of H. variegata. The cylindrical, tight sheaths place it here rather than with the species just named. In dried plants the sheaths are liable to be slightly ampliated. Washington to Alaska.