Thanks, kimmsr. Now that I was able to narrow my search I googled "Annual Bluegrass" and that is exactly what it is. Now I need to figure out if it is a desirable grass or just more weeds and how to get rid of it if it is a weed. (I wonder if Haltz will prevent it from sprouting again next year?)

Poa T (rough bluegrass) possibly?

Thanks, Carol. I think you're right about the top picture being little barley. Hooray! However, the second is definitely NOT crabgrass. The seed heads are branched (dallisgrass), not helicopter (crabgrass). Here's a photo from the internet showing the difference between the two. Dallisgrass on the left, crabgrass on the right. The seed heads on my weeds look like the ones on the left. I mowed recently, but I can take more pictures of Weed#2 in a few days, if needed.

no. not sure what that is. roughstalk bluegrass is notable for very thick seedhead stalks and not very dense. seedheads looks more robust on emergence but when it finally flowers, looks like regular bluegrass. that seedhead doesn't look like any of the poa types.