Mo. Rev. Stat. § 263.262
The existence or growth of Johnson grass in an electing county is hereby declared to be a public and common nuisance and the prosecuting attorney for each county shall have the duty to bring an action in the circuit court of the county to enjoin such nuisance. The action shall be in the name of the state of Missouri and shall be tried as a suit in equity before the court, and shall be against all persons permitting or maintaining such nuisance. The complaint in said action shall recite that thirty days' advance notice of the action has been served upon the defendants thereto, and that said defendants have taken no suitable action to comply with the provisions of the law prior to the filing of the complaint. Any landowner whose land is adjacent to or within one hundred feet of land on which such nuisance is permitted or maintained and who is undertaking a Johnson grass control program may bring a civil action for injunction against any person permitting or maintaining such nuisance and shall, in addition to injunctive relief, be entitled to recover as a penalty the sum of five hundred dollars as well as a reasonable attorney fee and any actual damages sustained as a result of such nuisance.
§ 263.262, RSMo