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

Eleocharis obtusa (Willd.) Schult.
blunt spike-rush (blunt spikerush; egg-shaped spike-rush)
Cyperaceae (Sedge family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #11515)

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Distribution of Eleocharis obtusa
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Species Information

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Annual (rarely perennial), tufted herb from fibrous roots; stems usually erect, several- to many-ribbed, 5-50 cm tall.
Sheaths firm, blunt; blades lacking.
Spikes solitary, terminal, egg-shaped, (2) 5-13 mm long, many-flowered (rarely less than 40).
Scales 1.7-2.5 mm long, egg-shaped to nearly circular, the lowest ones sometimes empty, purplish or brownish with pale, translucent margins and greenish midribs; perianth bristles mostly 6 or 7, equalling or surpassing the achenes, or reduced or lacking, with fine barbs directed backwards, brownish; stigmas 2 or sometimes 3; achenes lens-shaped, straw-coloured to dark brown, smooth and shiny, (0.8) 1-1.5 mm long including the flattened, broad-based tubercles, which are appressed to the summits of the achenes, 1/2 to as wide as the achenes, and up to 1/2 as long as them.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

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

Habitat / Range

Marshes, mud flats and wet meadows in the lowland and montane zones; frequent in SW BC, rare in the Queen Charlotte Islands, SC and SE BC; circumpolar, disjunct E to ON, PQ and NS and S to MA, PA, IN, MO and OR; Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Eleocharis obtusa

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) 615 736 805
Slope Gradient (%) 0 0 0
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
6 7 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: IDF(2)


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

Eleocharis diandra var. depressa Fernald
Eleocharis obtusa var. ellipsoidalis Fern. ex Svens.
Eleocharis obtusa var. gigantea (C.B. Clarke) Fern.
Eleocharis obtusa var. jejuna Fern.
Eleocharis obtusa var. obtusa (Willd.) Schult. [superfluous autonym]
Eleocharis obtusa var. peasei Svens.
Eleocharis ovata var. obtusa (Willd.) Kⁿk.
Scirpus obtusus Willd.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References