Calamagrostis stricta subsp. inexpansa (Timm) Koeler (A. Gray) C.W. Greene
slimstem reedgrass (northern reedgrass)
Poaceae (Grass family)

Introduction to Vascular Plants

Photograph

Once images have been obtained, photographs of this taxon will be displayed in this window.Click on the image to enter our photo gallery.
Currently no image is available for this taxon.


Map

E-Flora BC Static Map

Distribution of Calamagrostis stricta subsp. inexpansa
Click here to view the full interactive map and legend

Species Information

General:
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.
Leaves:
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.
Flowers:
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.
Notes:
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

SourceThe Illustrated Flora of British Columbia

Illustration

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

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

Ecology

Ecological Framework for Calamagrostis stricta ssp. inexpansa

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

Avg

Min

Max

Elevation (metres)
912 5 1850
Slope Gradient (%)
4 0 80

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

201 10 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
5 2 8
Modal Nutrient Regime
Class
D
# of field plots
 species was recorded in:
133
Modal BEC Zone Class
IDF

All BEC Zones (# of stations/zone) species was recorded in

BG(4), BWBS(34), CWH(1), ESSF(13), ICH(2), IDF(37), MH(4), MS(1), SBPS(11), SBS(15), SWB(1)

Habitat and 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.

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Calamagrostis californica Kearney
Calamagrostis canadensis var. acuminata Vasey ex Shear & Rydb.
Calamagrostis canadensis var. arcta Stebbins
Calamagrostis chordorrhiza A.E. Porsild
Calamagrostis crassiglumis Thurb.
Calamagrostis expansa (Munro ex Hillebr.) Hitchc.
Calamagrostis fernaldii Louis-Marie
Calamagrostis hyperborea var. americana (Vasey) Kearney
Calamagrostis hyperborea var. elongata Kearney
Calamagrostis hyperborea var. stenodes Kearney
Calamagrostis inexpansa A. Gray
Calamagrostis inexpansa var. barbulata Kearney
Calamagrostis inexpansa var. brevior (Vasey) Stebbins
Calamagrostis inexpansa var. inexpansa
Calamagrostis inexpansa var. novae-angliae Stebbins
Calamagrostis labradorica Kearney
Calamagrostis lacustris (Kearney) Nash
Calamagrostis lapponica var. brevipilis Stebbins
Calamagrostis pickeringii var. lacustris (Kearney) Hitchc.
Calamagrostis robertii A.E. Porsild
Calamagrostis stricta var. brevior Vasey
Calamagrostis stricta var. lacustris (Kearney) C.W. Greene