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

Trichophorum alpinum (L.) Pers.
Hudson Bay clubrush (alpine bulrush)
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #10740)

E-Flora BC Static Map
Distribution of Trichophorum alpinum
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Alpine clubrush (a.k.a.) alpine cotton-grass, is a native, perennial rhizomatous species that is found in North America at higher latitudes. It is a distinctive circumpolar peatland species which typifies sites of mineral enrichment, where it occurs with other mineral-loving species such as cattails. In BC, it is found across the province, exclusive of the coast islands, in bogs, swamps, fens and wet meadows in the montane and subalpine zones. Flowers occur in solitary spikes. Alpine cotton-grass differs from true cotton-grasses (genus Eriophorum) in having few (6-8) bristles, while cottongrasses typically have lots of bristles. View a video of this species in the field, with Tony Reznicek

Species Information

Click on the image below to view an expanded illustration for this species.

Perennial herb from short, freely rooting rhizomes; stems more or less densely clustered, in rows, sharply triangular in cross-section, rough on the angles, (5) 10-40 cm tall.
More or less reduced, scalelike at the base of the stems, with 1 or sometimes 2, more normally-developed leaves above the base; sheaths straw-coloured to brownish, not cross-wrinkled; blades narrow, 5-12 mm long, rough on the margins, the hairs directed forward or upward, the tips firm, blunt, somewhat expanded and cartilaginous.
Spikes solitary, terminal, medium or light brown, 5-7 mm long, many-flowered; involucral bracts lacking.
Scales 2 or 3, chestnut, lanceolate to egg-shaped, blunt, the lowermost egg-shaped, up to as long as the spikes, with prominent, thickened midribs which are exserted as broad, blunt awns or small, short, abrupt points, 0.5-2 mm long; perianth bristles 6, white, flattened, smooth, crisped, elongate, much surpassing the scales, at maturity forming silky white tufts extending 1-2.5 cm beyond the end of the spikes; achenes purplish-brown, 3-angled, narrowly egg-shaped, about 1.5 mm long, minutely abruptly sharp-pointed.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Bogs, swamps, fens and wet meadows in the montane and subalpine zones; infrequent in BC east of the Coast Mountains; circumpolar, N to AK, YT and NT, E to NF and S to ME, MA, NY, MI, MN, MT and ID; Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Trichophorum alpinum

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) 560 854 1980
Slope Gradient (%) 0 0 15
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
40 343 286
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 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: ESSF(1), ICH(7), MS(3), SBS(32)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Baeothryon alpinum (L.) Egor.
Eriophorum alpinum L.
Leucocoma alpina (L.) Rydb.
Scirpus hudsonianus (Michx.) Fernald

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References