Asked August 03, 2015, 8:36 PM EDT
Hopkins County Texas
It is a broad leaf plant. It looks like a Sericea Spp.
The weed came from a contaminated near by plot or contaminated hay. The important part is to treat to kill it when is small. This time of the year plants (and weeds included) protect themselves by stopping their metabolism and herbicide are less effective. Also, the weed is competing with your lawn and obviously winning. Have you done a soil test to make sure the conditions for the lawn are correct?