No alien or person who is not a citizen of the United States, shall acquire title to or own land in this state, and the Legislature shall enact laws whereby all persons not citizens of the United States, and their heirs, who may hereafter acquire real estate in this state by devise, descent, or otherwise, shall dispose of the same within five years upon condition of escheat or forfeiture to the State: Provided, This shall not apply to Indians born within the United States, nor to aliens or persons not citizens of the United States who may become bona fide residents of this State: And Provided Further, That this section shall not apply to lands now owned by aliens in this State.