Ohio Rev. Code § 927.682: Lythrum salicaria (purple loosestrife) plants or seed permit.

(A) Except as otherwise provided in division (B) of this section, no person and no political subdivision, agency, department, or instrumentality of the state shall sell, offer for sale, or plant Lythrum salicaria (purple loosestrife) plants or seed in this state without a permit issued by the director of agriculture. The director may issue permits to plant Lythrum salicaria for use in controlled experiments.

(B) The director, by rule, shall exempt from the permit requirement of division (A) of this section any variety of Lythrum salicaria that has been demonstrated to the director's satisfaction not to be a threat to the environment.