Missouri is at an interesting crossroads with regard to medicinal herbs.
In July, the Missouri governor signed into law a method to make hemp a legal commericial crop in Missouri. In January, the Missouri Dept of Agriculture
placed proposed laws on the web and asked for public comment. The proposed rules only allow for 2000 acres statewide and demand a farmer plant at least 10 acres and not more than 40 acres.
In the meantime, the 2018 Farm Bill took hemp off the list of schedule 1 prohibited crops and allows the states to set up rules for crops.
The day after Trump signed the Farm Bill, the state of Kentucky submitted its plan to the USDA for its farmers to begin planting crops. The state claims they have over 1000 applications from farms and 6700 acres
in production now.
Kentucky and Missouri were two of the states that grew commercial hemp crops before the ban in 1938. Kentucky had even developed special strains of hemp that are now apparently lost.
A primer and history of hemp
Missouri Proposed Hemp Laws
Medicinal Herb Resource Center