Equisetum arvense L.
Equisetum arvense L. var. alpestre Wahlenb.
Equisetum arvense L. var. boreale (Bong.) Rupr.
Equisetum arvense L. var. campestre Wahlenb.
Equisetum arvense L. var. riparium Farw.
Equisetum calderi B. Boivin
Horsetails are among the oldest members of the fern family, dating back 300 million years to the Carboniferous Period. They are largely unchanged from when dinosaurs ruled the earth. Field horsetails have high levels of silicon (10%!), and were once used to polish pewter and wood. They are found almost everywhere in North America.
Identification: See Equisetum for a comparison chart.
Edibility: The buds are eaten in Japan, but other portions of the plant and all other species of Equisetum are toxic.
Equisetum arvense at Skye Flora
Equisetum arvense on Wikipedia
Equisetum arvense on the USDA Forest Service's Fire Effects Information Database
Equisetum arvense on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Equisetum arvense on Calflora
Equisetum arvense on eFloras
Cobb, Boughton, Farnsworth, Elizabeth & Lowe, Cheryl, Peterson Field Guides: A Field Guide to Ferns and Their Related Families of Northwestern and Central North America, Houghton Mifflin Company, 2005, p. 340
Equisetum arvense description by Thomas H. Kent, last updated 5 Oct 2016.