Ask Mr. Smarty Plants

Calyptocarpus vialis (Straggler daisy), also called Horseherb, seems to be native in your county.  It is usually considered to be a weed, but many people appreciate its properties.  It is great as a groundcover in shady areas.  You may be able to find Straggler daisy in the wilds by looking in shady areas.  I will attach several photos to guide you. Perhaps one of your local nurseries carries it.  I have seen it in a vegetative state in nurseries but not as seed.  The following suggestion for planting Straggler daisy is lifted from a web site I found.

"HOW TO EASILY “SEED” AN AREA: Simply find a fast growing, blooming stand of Horseherb and mow it periodically using a lawnmower with a grass catcher attachment. Then thinly spread the Horseherb catchings (clippings) onto the area to be planted. Let the clippings dry for a few days then water or let the next rainfall germinate the very small seed which were collected during mowing. Horseherb will establish itself in stony, shady areas where grass will not grow well. NOTE: Horseherb DOES NOT kill or crowd out grasses; the grass thins or dies and the Horseherb covers the bare spots!"

I might suggest other possible plants for this site.  Ruellia humilis (Fringeleaf wild petunia), Salvia lyrata (Lyreleaf sage) and Phyla nodiflora (Texas frogfruit) should be suitable.