Xref: kermit rec.gardens:247098

I'm in Massachusetts, and my lawn has a smattering of these weeds.
I'd like to identify what they are so I can then find an appropriate
means to control or eliminate them. Here's my description:

The leaf is almost round, with a little indent where the stem meets
it. I thought it might be a violet of some kind, but I haven't seen
any flowers. Of course, they don't seem to grow very high, almost
like they know exactly how high the (cut) grass is because the mower
doesn't touch them. I tried a broadleaf weed control (Weed Be Gone)
and it's yellowing the edges but it doesn't seem to be killing it like
it kills dandelions and other weeds. Leaves seem to be around the
size of a a dime rnaging up to a half-dollar in size.

Anyone want to take a crack at ID'ing them from that description and
maybe offering some advice on killing them off without affecting my
lawn? TIA!

Mike