Tree fern. Ferns played a very important part in Maori life, with the bracken root being a staple food as well as being used for building and fencing. The fern could sometimes be a verbal symbol of chieftainship in the Maori language. At least forty-five kinds of spirals are used in Maori carving, the greatest elaboration being found in Auckland, Bay of Plenty and East Coast areas. Like carving, Maori tattoo or moko spirals more than likely had their origins in this fern. Collection of Mark and Carolyn Blackburn.