Monographs Details: Hippochaete prealta var. intermedia Farw.
Authority: Farwell, Oliver A. 1916. The genus Hippochaete in North America, north of Mexico. Mem. New York Bot. Gard. 6: 461-472.
Family:Equisetaceae
Discussion:

Equisetum hiemale var. intermedium A. A. Eaton, Fern. Bull. 10: 120. 1902, pp., and in Gray's New Manual, 53. 1908.

The sheaths are ampliated but not campanulate, and the teeth are caducous. Described by Mr. Eaton as with the anatomy of Equisetum hiemale but material distributed by him shows a variable anatomy, sometimes that of H. prealta sometimes that of H. laevigata. Collected at Port Huron, Michigan, by Mr. C. K. Dodge. It has been found in various localities from the Atlantic to the Pacific and may be looked for whenever H. laevigata and H. prealta var. affinis may be found in close association.