Mo. Rev. Stat. § 355.321: Directors' qualifications.

1. All directors must be natural persons. The articles or bylaws may prescribe other qualifications for directors.

2. A board of directors must consist of three or more persons, with the number specified in or fixed in accordance with the articles or bylaws.

3. The number of directors may be increased or decreased, but to no fewer than three, from time to time by amendment to or in the manner prescribed in the articles or bylaws.