Ricky Linex, a friend and excellent plant id man, identified it for us.  see below:

Chuck,

This looks like one of the Agalinis species, perhaps Agalinis heterophylla, Prairie agalinis. Matured plants will turn reddish-purple and then black with round fruit pods about ¼ inch in diameter with numerous dust-like seeds inside. This is a hemi-parasitic plant that has green growth but still parasitizes other plant roots for nutrients, sometimes causing those plants to die. A common name for this plant is “grass killer”. Native and pretty