A closer photo of the flowers would help. I downloaded it and zoomed in but still can't get enough resolution.
It's not any of the Salvia that are native to Missouri. I wonder if it is Salvia sclarea though, which has escaped in Missouri? It looks like there are some bracts beneath the flowers from your photo, which along with the leaves could suggest Salvia sclarea, but a close-up would be very helpful.
