Wetland Plants of Wisconsin

Calamagrostis canadensis (Michx.) P.Beauv.
blue-joint grass
live plants
spikelet with labels

Calamagrostis canadensisis is one of the most important native wetland grasses in Wisconsin. It is still widespread and abundant in northern Wisconsin, but it has diminished dramatically in southern Wisconsin, probably due in large part to displacement by the invasive species, Phalaris arundinacea (reed canary grass). C. canadensis can form tussocks every bit as impressive as those of Carex stricta (tussock sedge).

If you are learning to identify grasses, this is a good example of a species for which each spikelet contains a single floret (see labeled photo above). One of the commonest difficulties in discerning the species of Calamagrostis lies in the distinction between infloresence "mostly open" versus inflorescence "narrow and contracted". Keeping in mind that the shape of the inflorescence varies somewhat from one individual to the next and even for the same plant at different seasons, a comparison photograph is provided. Calamagrostis inexpansa (=C. stricta subsp. inexpansa) is much less common and appears to be associated with more basic sites than does C. canadensis.

known Wisconsin distribution


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