Common Name: COMMON HORSETAIL
Coefficient of Conservatism: 0
Coefficient of Wetness: 0
Wetness Index: FAC
Physiognomy: Nt Fern Al

Ubiquitous in a wide range of sunny or shaded habitats except very wet and very dry sites, including fields, forests, ditches, shores, meadows, roadsides, railroad embankments; sometimes weedy in yards and gardens.

Normally dimorphic, the fleshy pale pinkish-brown fertile stems appear in April or May, quickly shed spores, and die down soon afterwards. They are a striking feature of some early spring roadsides and fields. The green stems appear slightly later and last all summer. Sun and shade forms of the green stems may look very different, with shade forms being very graceful with long spreading branches, these occasionally (but never regularly) branched again. Plants of paths and other areas with heavy trampling may be spreading or even essentially prostrate.

Rarely, probably mostly stimulated by injury, the green stems of E. arvense will bear a terminal cone. These plants may simulate the hybrid E. ×litorale (see below), but differ in having a much narrower central cavity, ca. 1/4 the stem diameter, and also not occurring in the typical wetland habitat of E. ×litorale. Very rarely, the pinkish-brown fertile shoots may become green and even grow branches, thus simulating the habit of E. pratense or E. sylvaticum. From E. sylvaticum they differ in lacking the coppery sheath teeth and from E. pratense they differ in lacking stem papillae. See the key for additional distinctions.

Equisetum ×litorale (E. arvense × E. fluviatile), a rather uncommon hybrid, is known in Michigan from Grand Traverse, Mackinac, Monroe, Oakland, St. Clair, Washtenaw, and Wayne Counties. It resembles a large E. arvense, but with green shoots bearing a terminal cone and having a central cavity about 1/ 2 to 3/4 as wide as the stem.

A. Klain

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Counties
Alcona
Alger
Allegan
Alpena
Antrim
Arenac
Baraga
Barry
Bay
Benzie
Berrien
Branch
Calhoun
Cass
Charlevoix
Cheboygan
Chippewa
Clare
Clinton
Crawford
Delta
Dickinson
Eaton
Emmet
Genesee
Gladwin
Gogebic
Grand Traverse
Gratiot
Hillsdale
Houghton
Huron
Ingham
Ionia
Iosco
Iron
Isabella
Jackson
Kalamazoo
Kalkaska
Kent
Keweenaw
Lake
Lapeer
Leelanau
Lenawee
Livingston
Luce
Mackinac
Macomb
Manistee
Marquette
Mason
Mecosta
Menominee
Midland
Missaukee
Monroe
Montcalm
Muskegon
Newaygo
Oakland
Oceana
Ogemaw
Ontonagon
Osceola
Oscoda
Otsego
Ottawa
Presque Isle
Roscommon
Saginaw
Sanilac
Schoolcraft
Shiawassee
St. Clair
St. Joseph
Tuscola
Van Buren
Washtenaw
Wayne
Wexford

Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January, 23, 2025
https://lsa-miflora-p.lsait.lsa.umich.edu/#/record/1197