Patches of this weed starting showing up in my yard mid-July. It sprouts from its roots and weaves its way horizontally through the grass in all directions. It creates a tangled thick mat and it only grows bigger because the lawn mower doesn't cut that low. You can untangle and fluff it up above the grass line, pull it together like your tying a ponytail, then pull the weed with its roots out of the ground. This is spreading like wildfire and I can't seem to find any pictures of it online. Need help identifying it.
