I have looked almost everywhere in order to ID this bloom with no luck. Some blooms do arrive close but not quite. I live just outside of Big Bend National Park in Terlingua, TX. On a hike into Dog Canyon we encountered a light blue bloom. One bloom per thin grassy stalk. The closest resemblance of the bloom is of Phlox. However, bloom is a very baby blue. The pistil and stamen stand upright prominently in the center of the flower. Bloom has five petals and is also cupped and each petal comes to a subtle point. There is no separation or space between the petals but overlap the one next to it. I have a photo if there was a way I could send it. Soil is sandy next to a dry wash. Bloom was in November.
Here are some possibilities for your plant. All of the suggested plants below have been recorded in or near Big Bend National Park. Some are only vaguely similar to your description but I thought I should offer you some choices. I hope that one of them is the plant you saw. If not, please visit our Plant Identification page for links to several plant identification forums that will accept photos of plants for identification.
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