Eleocharis elliptica
 
Slender Spike-Rush

Spikelet

Greenbush Bog, 20 km West of Hudson Bay, SK on Highway #3
01-August-2017

Note the spikelet is about 5 mm long.  In general, the spikelets of E. elliptica range from 3 to 8 mm long.  In contrast, the spikelets of E. nitida are 14 mm long.