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

Carex obnupta L.H. Bailey
slough sedge
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #4408)

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Distribution of Carex obnupta
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Species Information

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Perennial, densely tufted herb from long, creeping rhizomes and fibrous roots, the roots with soft, reddish-brown hairs; stems 30-150 cm tall, arising a few or many together, longer than the leaves.
Sheaths tight, cross-wrinkled, reddish- to brownish-tinged at the base, the lowest ones breaking into threads; ligules as long as wide, rounded; blades 2 to 5 per stem, flat to channeled, borne on the lower 1/4 of the stem, 3-10 mm wide, the lower ones reduced.
Spikes 3 to 7, the terminal 2 (sometimes 1 or 3) linear, 1.5-6 cm long, long-stalked, with many male flowers, the lower spikes 2 to 4, cylindrical, 1.5-6 cm long, with female flowers, or some with male flowers above the female flowers, these short-stalked, spreading or nodding; bract subtending the lowest spike leaflike, sheathless, longer than the inflorescence, the bracts reduced above.
Perigynia broadly egg-shaped, leathery, 2.2-3.5 mm long, 1-1.2 mm wide, greenish or brownish, biconvex, smooth, faintly nerved, marginally 2-ribbed, the bases round, short-stalked, beakless or short-beaked, the beaks 0.1-0.2 mm long, entire or nearly so; female scales lanceolate, long-pointed or awned, as wide as and much longer than the perigynia, reddish-brown to dark brown, with 3-nerved, lighter centres, with narrow, translucent margins; stigmas 2; achenes lens-shaped, sometimes constricted in the middle, smooth, 1.6-2.2 mm long.

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

Swamps, marshes, riverbanks, wet meadows and alluvial forests in the lowland zone; common in S coastal BC; S to CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Carex obnupta

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 98 1230
Slope Gradient (%) 0 4 75
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 215 330
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: CDF(36), CWH(239), MH(1)

Ecological Indicator Information

A shade-tolerant/intolerant, submontane to montane, Pacific North American sedge. Occurs in hypermaritime to submaritime cool mesothermal climates on wet to very wet, nitrogen-rich soils (Moder and Mull humus forms); its occurrence decreases with increasing elevation and continentality. Scattered to plentiful (often dominant) in graminoid-dominated, semi-terrestrial communities; on water-collecting sites (fens, bogs, and marshes) with gleysolic or organic soils. A nitrophytic species characteristic of nutrient-rich 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 cool mesothermal.

Synonyms and Alternate Names

Carex magnifica Dewey ex Piper

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References