This plant is a Menzella, sometimes called stickleaf because the leaves may stick to you. I have only found one of these on my ranch even though i have some sandhills. I found it two years ago while cutting hay. I took the picture of the one I showed several years back. I had a Sandhill pasture leased then and there were quite a number of them there. I identified them as "Tenpetal Menzella". That name was not quite correct as it is the Bractless Menzella that grows in this area "Menzella nuda" It is quite common, now that I recognize it I have seen it along highway 20 in Nebraska and along the western part of highway 30. and have seen Menzellas in the South Dakota Badlands.
It blooms in late July and in August. Blossoms open in late afternoon or evening. I believe Larson and Johnson call it tenpetal blazing star in their book.