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

Carex rostrata Stokes
swollen beaked sedge (beaked sedge)
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Bryan Kelly-McArthur  Email the photographer   (Photo ID #89653)

E-Flora BC Static Map
Distribution of Carex rostrata
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Species Information

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Perennial, tufted herb from short-creeping rhizomes; stems 30-70 cm tall, triangular, smooth, except slightly rough below the inflorescence, slightly longer than the leaves.
Sheaths tight; ligules as long as wide; blades 4 to 8 per stem, borne on the lower 1/2 of the stem, 1.2-4.5 mm wide, folded or channeled, with silica papillae on the upper surface, cross-walled; lower leaves reduced, persistent.
Spikes 3 to 6 (8), the terminal 1 or 2, sometimes 3 or 4, linear, 1.5-5 cm long, long-stalked, with many male flowers, the lower 2 to 4 spikes cylindrical, 3-6.5 cm long, with female flowers, short-stalked, the lowermost ones spreading; bracts subtending the lowest spike leaflike, sheathless, the lowest one longer than the inflorescence.
Perigynia egg-shaped, 5-9 mm long, 1.7-3 mm wide, yellowish-green to reddish-brown, somewhat inflated, smooth, shiny, strongly nerved, rather abruptly contracted into beaks, the beaks 1.5-2 mm long, bidentate, with straight teeth; female scales lanceolate to egg-shaped, pointed, rarely awned, narrower and shorter than the perigynia, yellowish- to chestnut-brown, with lighter centres and narrow, translucent margins; stigmas 3; achenes 3-angled, 2.5-3 mm long.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
Source:  The USDA

Habitat / Range

Peat bogs in the montane and subalpine zones, rare in BC east of the Coast-Cascade Mountains; circumpolar, N to AK, YT and NT, E to NF and S to MI, IL, MN, MT, ID and WA; Greenland, Iceland, Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Carex rostrata

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) 850 1089 1300
Slope Gradient (%) 0 0 1
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
45 0 135
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
4 5 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: ICH(4), MS(1)


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

Carex ×anticostensis (Fernald) Lepage
Carex ×anticostensis var. inflatior Lepage (pro nm.)
Carex ×anticostensis var. longidens Lepage (pro nm.)
Carex ×anticostensis var. minor Lepage (pro nm.)
Carex grahamii Boott.
Carex mainensis Porter ex Britton
Carex rostrata var. ambigens Fernald
Carex rostrata var. anticostensis Fernald

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References