Meadow Horsetail - Equisetum pratense
State Rank Reason (see State Rank above)
Equisetum pratense has accurately been identified to occur in a few places within three counties of Montana. This species can be easily mis-identified. Specimens deposited in herbaria outside of Montana will need to be examined before it can be demonstrated that this plant is more widely distributed.
Plants: Rhizomatous perennials. Stems annual, vegetative and fertile stems differing; central cavity < 2/3 the stem diameter (Lesica 2012); stem bases smooth; upper stem ridges with spreading, high, siliceous tubercles or transverse crests on the ridges (Hitchcock et al. 1969). Vegetative stems annual, 5–30 cm tall (Lesica 2012) or sometimes up to 50 cm (FNA 1993), 1–2 mm in diameter, ascending or erect, 10-18-ridged, pale green and branched (Lesica 2012), the central cavity 1/6 to 1/3 the diameter of the stem. Fertile stems are unbranched and brown (FNA 1993) in spring, becoming branched and green following spore release later in the season (Lesica 2012); both sheaths and teeth are longer on fertile stems than on vegetative stems (Hitchcock et al. 1969).
Branches: Occurring in regular whorls, ascending to widely spreading and arched (Hitchcock et al. 1969), solid (unlike main stem), with channeled valleys and 3 ridges; sheaths 3-5 x 2-4 mm (FNA 1993), green, slightly flared; the sheath teeth 1.5-3.2 mm, membranaceous, acuminate (McGregor et al. 1986) with a dark center and light margins (Lesica 2012), triangular, 8-18 in number; stem sheath shorter than first internode of the branch above it (FNA 1993). (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Cones mature in late spring (FNA 1993).
Equisetum pratense and E. arvense have sterile stems that are similar in appearance. The siliceous tubercles of E. pratense are high and conspicuous, whereas in E. arvense, they are low and inconspicuous to smooth or papillate. The stems of E. pratense are generally more slender as well (Hitchcock et al. 1994).
AB, BC, MB, NB, NL, NT, NS, ON, PE, QC, SK, YT; AK, CT, ID, IL, IA, ME, MA, MI, MN, MT, NH, NJ, NY, ND, VT, WI; n Eurasia to ne China, Japan (FNA 1993). Known in Montana only from Flathead, Powell and Broadwater Counties (Lesica 2012).
(Lesica's contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Moist woods and meadows (FNA 1993), shallow water of seeps, swamps, stream margins; valleys to montane (Lesica 2012). (Lesica's contribution from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Strobili: Borne on long peduncles, deciduous as or shortly after fertile branches become green (McGregor et al. 1986), blunt, 10–20 mm long, uncommon (Lesica 2012).(Lesica’s contribution adapted from Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX.)
- Literature Cited AboveLegend: View Online Publication
- Britton, N. L. and A. B. Brown. 1913. An Illustrated Flora of the Northern United States, Canada, and the British Possessions. 2nd Edition in 3 Volumes. New York, NY: Charles Scribner's Sons. B13BRI01PAUS.
- Flora of North America Editorial Committee, eds. 1993. Flora of North America North of Mexico. Volume 2. Pteridophytes and Gymnosperms. Oxford University Press, Inc., NY. xvi + 475 pp.
- Great Plains Flora Association (McGregor, R.L., coordinator, and T.M. Barkley, R.E. Brooks, and E.K. Schofield - eds.). 1986. Flora of the Great Plains. Lawrence, KS: Univ. Press Kansas. 1392 pp.
- Hitchcock, C. L., A. Cronquist, M. Ownbey, and J. W. Thompson. 1969. Vascular Plants of the Pacific Northwest. Part I: Vascular Cryptogams, Gymnosperms and Monocotyledons. Seattle, WA: University of Washington Press. 914 pp.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.