Possibly quackgrass, Elytrigia repens. Extremely common, often seen along roadways and is a frequent invader of garden beds. If so, you want to remove before it takes over. And it will try!!

Looks like Poa palustris to me, but just a guess? Elytrigia is a synonym for Elymus. Agrostis stolonifera is another possibility?

Ugh, why do grasses have to be so difficult with themselves!

There are so many grasses and they all look so similar. They are easier than sedges.http://floranorthamerica.org/Poa_palustris#:~:text=Poa%20palustris%20from%20drier%20woods,margins%2C%20and%20incurving%20lemma%20keels.

https://www.inaturalist.org/taxa/69931-Agrostis-stolonifera

Grasses aren't nearly as complicated as sedges. What are the pink and white clustered flowers in the background? They remind me of Marshallia, but that's an eastern genus. They could be milkweeds for all I know? You can probably pull off growing Asclepias cordifolia and the Serpentine Milkweed.

Poa palustris

If you want a decorative grass that will behave, Calamgros acutiflora, Karl Forester grass does not self seed, but it grows to 4-6 feet. I’m guessing that’s not what you’re wanting. However there are other small sized grasses that behave as well. GG and Jay could probably recommend some.

debra

Here are some extra photos if you think that that would help distinguish between the few guesses.

And yes, those are milkweed. I call it my mini-meadow, and it’s a mixture of natives and non-natives that seem to do well together, with an emphasis on milkweeds.

I’ve seen Asclepias cordifolia in the wild, but never tried to grow it. And a friend of mine has a serpentine milkweed that he just barely keeps alive. It’s such a strange habitat and recreating that up here is not trivial.

Ahh the pics are very helpful, thanks. Asclepias speciosa with green flowers? I was going to pursue Will Kelly's dream which was to grow every milkweed native to North America, but I realized it would be impossible to simulate their cinditions because some of them are so specialized. I tried growing cordifolia a couple times and it just shuts down in the midwest heat and humidity. Ive managed to overwinter A. fascicularis and subverticillata. The Monarchs prefer laying eggs on the subverticillata. I changed my focus and now I'm just tryibg to establish only the Asclepias species native to Illinois, and some of them are difficult. I've grown a few exotic Asclepiadoideae species like Oxypetalum(Tweedia) coerulea and solanoides that grew beauriful in pots and were also used as host plants. I've grown Calotropis procera and Asclepias nivea. I'm still experimenting, using varioous grass species, trying to find species that will play nicely with all my native plants.

I haven’t seen any monarchs for at least three years here in Portland. Pretty disappointing since are used to get at least one sighting each year up until then. Sic transit gloria mundi and all that, I suppose.

The green speciosa is a rare alba form. Even the stems have no red pigment. It, sadly, doesn’t come true from seed.

I need to try cordifolia since things are getting warmer here in northern Oregon in the past 10 years.

Do you think you are previous identification stands for the grass?