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

Carex rossii Boott
Ross's sedge
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #25119)

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Distribution of Carex rossii
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Species Information

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Perennial, densely tufted herb from short rhizomes; stems 5-30 (40) cm tall, densely clustered, longer than or sometimes equalling the leaves, purple-tinged at the bases.
Sheaths tight, persistent; blades flat, channeled above, smooth or somewhat rough, borne on the lower 1/4 of the stem, 1-4 mm wide, the lower ones slightly reduced.
Spikes 4 to 10, the terminal one unstalked or short-stalked, 5-15 mm long, with male flowers, the lower spikes 3 to 9, few-flowered, with female flowers, unstalked to short-stalked, 1 to 4 of these borne near the male spike and 1 or more borne near the bases of the stem, erect; bracts subtending the female spikes leaflike, sheathless or short-sheathing, from shorter than to 4 times as long as the male spike, the upper bracts reduced.
Perigynia elliptical to nearly globe-shaped, 3-4 mm long, 2.6-3 mm wide, green to straw-coloured, convex, finely short-hairy, with 2 prominent marginal nerves, the bases long-stalked, the beaks short and inconspicuous to slender and 0.4-1.8 mm long, shallowly bidentate; female scales egg-shaped and pointed on the upper perigynia to broadly lanceolate and awned on the lower perigynia, usually shorter and somewhat wider than the perigynia, brownish-green, with lighter midribs and translucent margins; stigmas 3, rarely 2; achenes 3-angled, smooth, 1.5-2 mm long.
Part of the poorly studied C. deflexa complex.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
Source:  The USDA

Habitat / Range

Dry to mesic open forests, rock outcrops and forest openings in all vegetation zones; common throughout BC except absent on the Queen Charlotte Islands; N to AK and YT, E to ON, and S to MI, NE, NM, AZ and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Carex rossii

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) 0 1189 2508
Slope Gradient (%) 0 35 250
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 185 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 2 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: AT(13), BAFA(2), BG(30), BWBS(12), CDF(1), CWH(71), ESSF(295), ICH(151), IDF(285), IMA(1), MH(2), MS(80), PP(40), SBPS(12), SBS(54), SWB(2)

Ecological Indicator Information

A shade-intolerant, submontane to subalpine, North American sedge distributed in the Pacific, Cordilleran, and Central regions. Occurs on very dry to moderately dry, nitrogen-medium soils, within boreal, temperate, cool semi-arid, and cool mesothermal climates. Its occurrence increases with increasing continentality and decreases with increasing precipitation. Sporadic on shallow stony or rocky soils in open-canopy forests; scattered on cutover areas on water-shedding sites. Characteristic of moisture-deficient sites.

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

Carex brevipes W. Boott
Carex deflexa var. rossii (Boott) L.H. Bailey
Carex diversistylis Roach

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References