Mich. Comp. Laws § 111.20

Sec. 20. All the provisions of law respecting delinquent taxes levied in townships shall apply to all taxes levied in any ward of the city, and be returned as delinquent to the county treasurer and the ward, in respect to taxes levied therein and returned to the county treasurer, as delinquent, shall, except as herein otherwise provided, be considered and treated as a township, and all provisions of law for the sale of lands for the payment of taxes levied for state, county and township purposes, and returned delinquent, shall apply to the return and sale of property for the non-payment of delinquent taxes levied in any ward of the city except as herein otherwise provided.