Mo. Rev. Stat. § 362.475

When any deposit is made by any person describing himself in making the deposit as trustee for another, and no other or further notice of the existence and terms of a legal and valid trust than this description shall have been given in writing to the bank or trust company, in the event of the death of the person so described as trustee, the deposit or any part thereof, together with the dividends or interest thereon, may be paid to the person for whom the deposit was thus stated to have been made.