I cannot seem to hurt/kill this weed and it has taken over my backyard. Ever since I had a patio added I'm assuming either the new dirt or new seed the contractor used has bombarded my back yard. I have tried many weed killers and the latest suggestion was nudsedge. Killers intended for this weed did absolutely nothing. Any help with a name of the weed and ways to get rid of it would be amazing! Thanks in advance!