Yes Laura! Although lawn burweed was described and obiviously something is a real pain in the pet later in the season this is field madder. Lawn burweed has an inconspicuous bloom. It turns into a spiny blankety blank that is totally unfriendly to bare feet or paws. IÕve been seeing more and more field madder for the last four or five years In the North central West Ga area IÕve found only three sites in over thirty years with lawn burweed. Those sites have all been in NE Carroll Co. Two of those sites were noted in the spring of 2017 and this spring.

Information link on organic herbicides. http://ucnfanews.ucanr.edu/Articles/Feature_Stories/Organic_Herbicdes_-_Do_They_Work/

“The lavender flowers” looks like Sherardia arvensis ( blue field-madder). Sorry, I’m not knowledgeable in organic herbicides to share. Maybe you could check with the experts from the second link for further help in organic herbicides method. Best wishes! Link for blue field-madder. Click on images to enlarge. https://en.wikipedia.org/wiki/Sherardia

see my website notes on burweed