Glyceria canadensis var. canadensis
Spikelets 5-8 mm, with 4-10 florets. Lower glumes 1.6-2.4 mm; upper glumes 1.8-2.5 mm, acute; lemmas 2.4-4 mm. 2n = 60.
Glyceria canadensis var. canadensis grows through¬out the range of the species. The spikelets bear some resemblance to those of Bromus briziformis, otherwise known as rattlesnake brome, hence the vernacular name "rattlesnake mannagrass".
"decumbent" is not a number.