E-Flora BC: Electronic Atlas of the Flora of British Columbia

Equisetum telmateia Ehrh.
Giant Horsetail (Swamp Willowherb)
Equisetaceae (Horsetail family)

Introduction to Vascular Plants

© Grant Christensen  Email the photographer   (Photo ID #86631)

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Distribution of Equisetum telmateia
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Equisetum telmateia ssp. braunii

Species Information

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Perennial from a felty-hairy, blackish, tuber-bearing rhizome.
Sterile stems 15-150 cm tall, 5-20 mm thick, their central cavity more than 2/3 the stem diameter, regularly and abundantly branched, the sheaths with 15-30 teeth, the teeth with dark tips; branches in regular whorls; fertile stems appearing in spring before sterile stems, 10-40 cm tall, pale brown, unbranched, dying when the spores are shed, the sheaths 4-8, pale brown with 20-40 darker teeth.
4-8 cm long, hollow, rounded at the tip.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist to wet alluvial forests, loamy banks, cliffs, seepage areas, gullies, swamps, and roadsides, in the lowland and montane zones; frequent in coastal BC, rare east of the Coast-Cascade Mountains; S to CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Equisetum telmateia

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 2 190 1010
Slope Gradient (%) 0 7 70
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
20 107 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 6 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: BWBS(2), CDF(57), CWH(60), IDF(2), PP(1)

Ecological Indicator Information

A shade-tolerant/intolerant, submontane to montane, European and Western North American horsetail (mainly in the Pacific region, less in the Cordilleran region, marginal in the Central region). Occurs in maritime to submaritime cool mesothermal climates on fresh to very moist, nitrogen-rich soils (Moder or Mull humus forms). Inhabits exposed mineral soil in broad-leaved stands on water-receiving (floodplain, seepage, and stream-edge) sites with fast-flowing groundwater near the ground surface. Its occurrence decreases with increasing latitude, elevation, and continentality. A nitrophytic species characteristic of alluvial floodplain forests.

SourceIndicator Plants of Coastal British Columbia (Information applies to coastal locations only)

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