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

Calamagrostis stricta (Timm) Koeler
slimstem reedgrass
Poaceae (Grass family)

Introduction to Vascular Plants

© Ryan Batten  Email the photographer   (Photo ID #25841)

E-Flora BC Static Map
Distribution of Calamagrostis stricta
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Species Information

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Perennial, loosely tufted, fine to coarse, slender to robust grass from fibrous roots and rhizomes; stems unbranched, 20-120 cm tall, with 2 to 4 nodes.
Sheath summits smooth or rarely with tufts of hair; leaf blades often in-rolled or stiff and flat, 2-6 mm wide, 5-30 cm long, smooth to rough or glaucous above, smooth or rough below; ligules 1-5.5 mm long, entire or with jagged margins at the tips.
Inflorescence a stiff, erect, congested panicle 5-20 cm long, the longer branches 1.5-5 cm long, spikelet-bearing for over 1/2 their length; spikelets 2-4.5 cm long, 1-flowered; glumes 2-6 mm long, subequal, thin and smooth or thick and opaque, smooth to rough short-hairy, inconspicuously rough on the keels, occasionally translucent on the margins, sometimes purple-tinged; lemmas 2-5 mm long, notched or 4-toothed at the tips, finely rough, bearing stout to slender, straight or sometimes twisted and bent awns attached 1/3-1/2 above the base of the lemmas and extending about to the tips of the glumes or slightly beyond, sometimes shorter than the glumes, the callus hairs of varying length, up to 1/2 to 3/4 as long as the florets; paleas 1/2 to almost as long as the lemmas, thin, usually translucent, sometimes inconspicuously rough short-hairy along the nerves; rachillas about 1 mm long, bearded with hairs as long as those of the calluses; anthers either normally or poorly developed, then sterile and remaining closed at maturity.
Two subspecies occur in BC. The ssp. inexpansa includes many apomictic forms and intergrades with the ssp. stricta. Coastal forms of ssp. inexpansa with hard, stiff glumes have been separated as C. crassiglumis, but these seem to be forms that are capable of reproducing asexually part of the time and easily fall within this morphologically variable species. The subspecies may be separated as follows:

1. Glumes thick, often opaque, 3-6 mm long; blades 3-6 mm wide, flat, rough above, usually somewhat rough below; ligules 3-6 mm long, often with jagged margins....................ssp. inexpansa (A. Gray) C.W. Greene

1. Glumes thin, 2-4.5 mm long; blades 2-4 mm wide, often in-rolled, smooth to rough above, usually smooth below; ligules 1-3 mm long, usually entire....................ssp. stricta

Source: The Illustrated Flora of British Columbia

Habitat / Range

Mesic to wet meadows, gravel bars, fens, marshes, lakeshores and open forests in the montane to alpine zones; ssp. inexpansa - common in BC east of the Coast-Cascade Mountains, infrequent in coastal BC; ssp. stricta - frequent in N BC east of the Coast-Cascade Mountains, rare in SC and SE BC; ssp. inexpansa - amphiberingian, N to AK, YT and NT, E to NF and S to ME, NH, NY, OH, IN, NE, NM, AZ and CA; NE Asia; ssp. stricta - circumboreal, N to AK, YT and NT, E to Labr. and S to NH, MI and CO; Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Calamagrostis stricta

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) 80 1101 1920
Slope Gradient (%) 0 8 78
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 225 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 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: BG(2), BWBS(29), CWH(1), ESSF(31), ICH(3), IDF(21), MS(12), SBPS(28), SBS(18), SWB(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.

Taxonomic and Nomenclatural Links

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General References