Calylophus species? Texas primrose?

Oenothera triloba

What is striking is the many shaft-like pistils. That does look like a good match for Oenothera triloba (Stemless evening-primrose). It is a primrose, but not the Texas one. Thank you! Leaves seem a good match as well. It's supposed to bloom in the evening, and that's when I'm seeing it. I don't know where it's been hiding for the last few decades, but it seems to be somewhat invasive, so I suspect I'm going to see a lot more of it! It seems that there are seed pods that ripen, break open and scatter seeds.

Every flower has only 1 pistol with 4 stigmas. or 1 four lobed, cross shaped stigma,(depending on interpretation) "but not the Texas one." Texas has 56 Oenothera species, and triloba is common in the Dallas area. O. triloba also only has basal leaves,(stemless). The pink things are the spent flowers. Im not sure why they are pink, but many flowers develop a pink hue when they age. Perhaps to signal to pollinators that they won't get a nectar reward, so they don't waste their time.

Dave, there aren't any Calylophus species currently. They were moved to Oenothera. Calylophus is a section of Oenothera. Oenothera triloba is in section Lavauxia, subsection Lavauxia.
https://en.wikipedia.org/wiki/List_of_Oenothera_species

In my plant there were lots of those pink things. It is is a little mystifying that those are spent flowers, because I go down there almost every day, and this was the first day I saw those bright yellow blooms. But if they only bloom in the evening, I might well have missed them. Also, there are clearly more than four of those shaft-like thingies in the middle of each flower.

The 'shaft like thingies' are of two types: a stigma atop a style containing the female parts and stamens holding the male pollen. Each bloom in the picture definitely only has one single stigma with a cross shaped top. Oenothera flowers last a very short time. The pink things are spent flowers from previous days. Jay is correct.