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

Source:  The Illustrated Flora of British Columbia

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.

Illustration Source:  The Illustrated Flora of British Columbia

Flower Colour:
Purple

Blooming Period:
Late Spring

Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall

Source:  The USDA

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