Pas facile à identifier dans cet état...
Cyperus diandrus (Umbrella flatsedge)
https://www.minnesotawildflowers.info/grass-sedge-rush/umbrella-flatsedge
« Has clusters usually with 6 or more spikelets, floral scales that are maroon to reddish-brown along the edges, especially at the tip end, and long, persistent styles. »
Cyperus bipartitus (Shining flatsedge)
https://www.minnesotawildflowers.info/grass-sedge-rush/shining-flatsedge
« Has clusters usually with 5 or fewer spikelets, floral scales that are maroon to reddish-brown except maybe along the edge, especially at the tip end, and the style is not persistent. »
Comparison of Cyperus bipartitus and Cyperus diandrus spikelets
https://www.minnesotawildflowers.info/udata/r9ndp23q/grass/cyperus-diandrus-bipartitus-spikelet.jpg