It is certainly an Oenothera but I can't tell you which species as I am only familiar with O biennis.

This weedy thing can really self-sow with abandon if you have it in or near your yard, and can take over if you let it go to seed. It is able to grow with virtually no summer water, and will germinate even in the middle of summer. My advice would be to eliminate it before it takes over, if you have it in your garden. The long tap root is very deep, and will resprout if not completely removed.

This is my first time posting on this forum, hope you don't mind but I couldn't resist when I saw the photo. It looks like what we in Central Texas call "beggar lice," don't know the scientific name. You could call it a wildflower because of its lacy foliage and little white flowers, but it's also an annoying weed that produces copious amounts of slightly barbed seeds, which hitch a ride by clinging to your clothing, to your dog's fur, or anything else it can stick to, thereby broadcasting and reproducing itself to the point that it's almost impossible to control. Every day I hand-pull as many of these as I can and barely make a dent. We spend the summer picking the seeds out of the dogs' ears and off the rugs. They even get in the laundry and stick to the towels. Can you tell I hate these things? But some people like them because they are pretty.

The folks on the "Name That Plant" forum helped me identify all of them very quickly. For reference, they are: Crimson Clover (Trifolium incarnatum) - first 2 pics Blue-Eyed Grass (Sisyrinchium sp.) - 3rd Nuttallanthus sp. (probably texanus) - 4th Verbena sp. (probably V. canadensis) - 5th