I have a pic of a lawn weed i am having problems getting rid of. It is
> popping up in different spots each year, and weed killer does not do > anything. >
>
>
Looks like field violet. Selective herbicides won't do the job, as you have already discovered. You can either start digging or try dabbing pure, undiluted roundup on the leaves with a Q-tip. I have to confess that I haven't actually tried the roundup on this weed, but suspect it will work. Perhaps someone else in this group has tried it.
Peter H