.....Scott Namestnik!!!!!! Within hours of posting the quiz, Scott and his botanical super-sluething went to work. He came up with Rhamnus lanceolata and that is correct!! Nice work, Scott!
Here is a photo of the whole plant (flowers and all). It is a strange little shrub that I seldom see in Missouri and never elsewhere. It seems to like edges of old fields, gravel roads and creeks. It is documented from most counties in Missouri, but one rarely sees it. Perhaps it is in decline due to the lack of thickets and shrubby habitats that were more common before extensive row-crop agriculture and the introduction of fescue. I'm sure fire suppression has something to do with it as well.