Thank you! That looks like it when I Googled it.

Not to negate anything said above, just to tweak the species slightly. Since there are no red spots on the leaves, it more closely resembles E. prostrata, although its' sizes and proclivity to become more upright is not something I can determine from the pics. There are other, similar species that have a more upright habit, and your location may shorten the list significantly.

If you happen to be one of the unlucky ones who's skin is sensitive to getting a rash from latex sap, you may want to pull these with gloves on.

E. maculata does not always have any distinctive spotting. And it and E. supine are typically treated as synonymous. Flowers on E. prostrata are extremely indistinct and a purple-pink color compared to the more prominent white flowers showing in the photo.

But it too is a possibility :-) They are all very similar. And the preferred botanical name now is Chamaesyce. But they've been euphorbias too long for me to change easily!

TY for the added details! I haven't committed the spelling of the new name to memory either. It may or may not happen. It does make more sense that not all of the HUGE collection of species in Euphorbia genus are that closely related.

I pulled a few and took a few more pictures. They have pretty shallow roots (1.5-2") and pull easily. The larger ones have about a 6-8" spread. The don't grow upward, only laterally through the grass. The mower doesn't even cut them (although I have the mower set to cut fairly high (a 5 on the 1-7 dial).

In fact that now makes me wonder if I should try a very low cut with the mower in an attempt to cut much of their leaves off, if that might help kill them? I'm guessing they'll just grow back though.

Here's one of the resources I checked once Gardengal game me a name to look up, and it does look very much like the pictures in this link:

https://www.scotts.com/en-us/library/weed-control/how-kill-spotted-spurge

I guess I'll try some crabgrass killer for lawns and see if that helps (probably Weed-B-Gon Plus Crabgrass Control).

Hand pulling would be the easiest and safest method. They are so very easy to pull. With their prostrate growth, mowing might not get all the flowers and seeds, and then. your problem will be worse.