Whenever in any cemetery or place of burial of human remains there is any known grave of a former soldier, sailor, or marine of the United States who was not dishonorably discharged from the service, the board of supervisors of any county as to territory, whether incorporated or not, within it, and the governing body of the city as to territory within it, with the consent of the officers who manage such cemetery or place of burial, if any may keep such grave properly marked and identified, and free from weeds and rubbish, and keep in decent order and repair and free from defacement, injury, and unlawful markings any tomb, monument, gravestone, wall, or other appurtenance to such grave.