Calamagrostis canadensis

Bluejoint Reedgrass

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The natural history of the northwoods


  • Calamagrostis, from the Greek, kalamos, "reed, cane", agrostis, "field grass, green provender"; hence "reedgrass"
  • canadensis, from the Latin, "of Canada"
  • Common Name, from
  • Other common names include: Bluejoint, Meadow Pinegrass, Canadian Reedgrass, Marsh Pinegrass, Marsh Reedgrass


  • Family Poaceae, the Grass family
  • Genus Calamagrostis,


  • Differs from all other grasses that have 1-flowered spikelets by its narrow bluish leaves not more than 1/3" broad and its delicate, open panicle.


  • A sod-forming, native, perennial, cool-season grass.
  • Long-lived; well developed fields may persist for 100 years.
  • Leaves elongated, very narrow, bluish, up to 1/3" broad, not hairy but rough to the touch. Panicle 4"-8" long, purplish with branches spreading.
  • Stems erect, unbranched, smooth, up to 5' tall. Blades numerous, generally 2'-4' tall.
  • Roots fiberous, shallow. Creeping underground rhizomes extensive.
  • Flowers: Borne singly in spikelets, with many spikelets on slender stalks, forming an open panicle; each spikelet up to 1/6" long; glumes narrow, pointed; lemma with a delicate awn not exserted beyond the entire spikelet. Flowering: May-August.
  • Fruit ellipsoid, yellow brown, smooth, about 1/16" long.
  • Very long, papery ligule. Stem branches about a foot off the ground.


  • Alaska to Quebec, and south to all but the SE United States.


  • The most common and widespread Calamagrostis in North America.
  • Throughout the boreal and temperate regions, in a wide range of habitats from lowland wet sites, semishaded woodlands, to windswept alpine ridges. Wet meadows, wet prairies.
  • Prefers moist sites but can survive a wide range of moisture levels. Cannot germinate under drought conditions, although very drought resistant once established.
  • Soils: Imperfectly to moderately well-drained soils, on both peat and mineral soils, but most often on peat; is adapted to a wide range of soil textures.
  • Tolerant of extremely acidic soils, (pH 3.5); moderately tolerant of saline soils.
  • An understory dominant or codominant in many early successional to climax riparian and cool, moist forest communities. Once established, a very dense stand may persist almost indefinitely, severely limiting the invasion of woody species.


  • Sprouts from surviving rhizomes following fire. It can also establish on burned sites by wind dispersed seeds.
  • Fire will kill aboveground vegetation and severe fires will also kill belowground rhizomes. Light surface burning tends to increase its abundance.


  • Trees:
  • Shrubs:
  • Herbs: Kentucky Bluegrass (Poa pratensis), Fireweed (Chamerion angustifolium), Beaked Sedge (Carex rostrata), tufted hairgrass (Deschampsia caespitosa)
  • Ground Covers:
  • Mammals:
  • Birds:




  • Reproduces by seed and vegetatively by rhizomes.
  • Sexual Reproduction: Flowers wind pollinated. Prolific flowering, however, occurs only in wetlands and recently disturbed sites. The winged seeds are very lightweight and easily wind-borne. Seed yields are low, but seed can remain viable in the soil for up to 5 years.
  • Vegetative Reproduction: Capable of producing an extensive network of rhizomes during a single growing season.
  • Phenology:
    • Leaf and stem production from early May to mid-June followed by significant vegetative growth of shoot biomass.
    • Flowering heads begin to emerge by mid-June
    • Flowering begins by late June to early July
    • Flowering peaks late June to mid-July.
    • Aboveground senescence begins mid to late August.


  • By seed, following cold stratification.
  • Division most successful method.


  • Disease: Susceptible to white top, a condition caused by insect or fungal damage of the lower stems. Not susceptible to snow mold.
  • Serious competitor of conifer seedlings on disturbed moist sites. Often produces a thick, "mulch" of litter which insulates the soil surface, causing the soil temperature to decrease. Cold soils could partially explain the poor growth of conifer seedlings that often occurs after planting in bluejoint reedgrass dominated sites.


Boreal border
Last updated on 10 August 1998