It is hereby declared unlawful for any person or persons, not the owner thereof, or without lawful authority so to do, to wilfully injure, deface, disfigure or destroy any fruit, shade or ornamental tree or shrub, or to injure, destroy, cut or pick any flower or plant, growing, standing, or being either on private ground or any street, parking, public park or place within the city. (1961 Code)