Equisetum palustre (Marsh Horsetail)

Plant Info
Also known as:
Family:Equisetaceae (Horsetail)
Life cycle:perennial
Habitat:part shade, shade, sun; wet; swamps, bogs, ditches
Fruiting season:summer
Plant height:10 to 18 inches
Wetland Indicator Status:GP: FACW MW: FACW NCNE: FACW
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

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Detailed Information

Leaves and stems: Leaf attachment: whorl

[photo of sheath and first internode] The sterile stem is green and has whorled branches that are spreading to ascending. The stem has a small central cavity and hollow branches. The “leaves” are reduced to a toothed sheath that surrounds the stem, with 5 to 10 black/brown teeth that have white or translucent edging. The first sheath on the branch (aka first internode) has 5 or 6 narrow teeth and the first branch internode is shorter than the stem sheath.

Fruit: Fruit type: spores on stalk

[photo of developing spore cone] Fertile stems are like the sterile stems but with a blunt-tipped, ½ to 1½ inch spore cone at the tip. The cones mature in summer.


Marsh Horsetail does not tend to create large colonies like many other Equisetum species do. It may be confused with Field Horsetail (Equisetum arvense) or Meadow Horsetail (E. pratense), both of which have 3 or 4 teeth on the branch sheath where E. palustre has 5 or 6, and solid branches where E. palustre are hollow. In addition, E. arvense is similar with spreading to ascending branches, but its first branch internode is longer than the stem sheath. E. pratense is similar to E. palustre with the first branch internode shorter than the stem sheath, but has spreading to drooping branches, not ascending.

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More photos

Photos courtesy John Thayer taken at Iron Springs Bog SNA, Clearwater County.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Luci - MN Valley Wild Life Refuge
on: 2014-08-25 09:31:39

There is a field of this plant about 10 miles from the MN Valley Wild Life Refuge. Many cyclists refer to the area as the "River Bottoms." The plant grows along a sandy section about 5-8 miles west of the foot bridge that crosses the river.

Posted by: luciearl - Lake Shore
on: 2019-07-15 08:33:25

I believe this is growing in the wetland that is off the trail, Cty Rd 77.

Posted by: Charles B. Quinlan
on: 2023-11-04 18:06:45

In Massachusetts Go Botany site Arthur Haines mentions that Equisetum palustre Marsh Horsetail is a poison plant to horses. Do recognize the species as detrimental to Horses. Sincerely Charles B. Quinlan

Posted by: K Chayka
on: 2023-11-04 18:28:37

Charles, all the Equisetum species can be toxic to varying degrees. We don't know if horses are more susceptible to the effects or not, or if this particular species is more toxic than others. Check with your veterinarian.

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