Invasive Plants of Wisconsin

Poa nemoralis L.
wood bluegrass
Family: Poaceae
population plants leaves stem inflorescence
population plant horizontal leaves plant base inflorescence
florets spikelet ligule ligule  
florets florets ligule ligule  

Poa nemoralis is an alien grass that appears capable of becoming an invasive species in some forests in Wisconsin. The culms are obviously clumped and the leaves spread horizontally. Also, I don't have the technical resources to reproduce it on the web page, but the rachilla is clearly pubescent within each spikelet. I have not seen the rare native Poa interior which is similar, but Poa nemoralis has very short ligules-- about 0.3 mm in the photos above (much shorter than in the native Poa interior) and leaves tend to continue farther up the stem that they do in Poa interior.

I have seen serious infestations of this grass in Forest, Oconto and Door Counties, but I suspect it is much more common than the record of vouchers indicates.

known Wisconsin distribution


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