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

Rhynchospora alba (L.) Vahl
white beak-rush (white beaksedge)
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Bryan Kelly-McArthur  Email the photographer   (Photo ID #85630)

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Distribution of Rhynchospora alba
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Species Information

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Perennial, densely tufted herb from fibrous roots; stems slender, more or less solid, triangular in cross-section, usually longer than the leaves, (8) 15-50 cm tall.
Sheaths straw-coloured, more or less persistent, closed; blades several, on the stem, the lowest more or less reduced, often to mere scales, the others slender and elongate, folded or triangular in cross-section to thick and flat, 0.3-1 mm wide.
Inflorescence of 1 to 3, compact, axillary or terminal heads, mostly 5-15 mm wide, the terminal head larger than the others, each head with several to many spikes, the spikes white, becoming pale brown, often with a whitish or pinkish tinge, mostly 3.5-5 mm long, 2- to 3-flowered; involucral bracts longer or shorter than the inflorescence, 0.5-6 cm long.
Scales egg-shaped or lanceolate, pale brown, translucent on the margins, spirally arranged within the spikes; perianth bristles 10 to 12, well-developed, minutely finely barbed backwards, surpassing the achene bodies and sometimes also the tubercles; achenes lens-shaped, 1.5-2.5 mm long; broadest above the middle, tapering to narrow, nearly stalked bases, capped by elongate, narrow awl-like tubercles, about 1/3 to 1/2 as long as the achenes.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Bogs and fens in the lowland and montane zones; frequent in and W of the Coast-Cascade Mountains in BC south of 56degreeN, rare in SC BC; circumpolar, N to SW AK, E to NF and S to ME, MA, NC, IN, IL, MN, ID and CA; West Indies, Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Rhynchospora alba

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) 10 278 1529
Slope Gradient (%) 0 5 45
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
2 357 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 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(5), CDF(9), CWH(123), ESSF(3), ICH(9), MH(2), SBS(4)

Ecological Indicator Information

A very shade-intolerant, submontane to subalpine, circum­polar sedge [transcontinental in North America (absent in Alberta and Manitoba)]. Occurs on wet to very wet, nitrogen­poor soils (Mor humus forms) within boreal, cool temperate, and cool mesothermal climates; its occurrence increases with increasing precipitation. Scattered in non-forested, semi­terrestrial communities on water-collecting sites; occasional on acidic sands. An oxylophytic species characteristic of nutrient-poor wetlands.

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


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

Rhynchospora luquillensis Britt.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References