Published: Aug. 12, 2020
dried fern leaves on paper

Field Horsetail (Equisetum arvense) is a cosmopolitan fern widespread throughout the Northern Hemisphere, found in moist sites along roadsides and riverbanks as well as in fields, marshes, pastures, and tundra. Today’s horsetails are ‘living fossils'—miniature descendants of an ancient plant lineage that once played a dominant role in the understory of Paleozoic forests. Some of those equiseta were large trees,Ìýand their fossils are abundant in coal deposits from the Carboniferous Period, or the Age of Ferns.ÌýÌý

Ferns and their allies, like club mosses and horsetails, have traditionally been grouped together as pteridophytes, a group of vascular plants that reproduce by spores rather than seeds. The spores of ferns are produced in tiny sacs, usually grouped in clusters called sori, and typically found on the underside of the leaf. As a primordial lineage reaching back 400 million years, to a time when planet earth had just begun to support terrestrial life, ferns maintain this early strategy of sexual reproduction.ÌýÌý

ÌýThere areÌý15-25ÌýÌýknown species of Equisetopsida. They share a unique growth form that distinguishses them from other ferns. Their stems look like they are made up of a combinationÌýof smaller segments stacked on top of one another. They are hollow and reinforced with silica, making them strongÌý(butt also rendering them toxic to their namesake—pun intended).


Common name: Field HorsetailÌý
Scientific name:ÌýEquisetum arvense
Location collected:ÌýFremont County, CO
Date collected:Ìý1 June, 1998
Collectors:ÌýRonald Hartman, M. Arnett, C. Hall, B. Jacobs, A. MorganÌý

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