Archaeometric studies of cordyline (TI) based on ethnobotanical and archaeological research
The prehistoric utilization of Cordyline (ti) in southern New Zealand was studied using a multidisciplinary approach. The ethnographic literature on the prehistoric use of Cordyline in the Pacific area and particularly in New Zealand was reviewed. Cordyline had several uses, the main ones being, food, cordage, medicine, and a material for plaiting. Cordyline terminalis is the commonest species in Oceania. It was also introduced into New Zealand by Maori, but there were four endemic species which provided food for the early inhabitants. Large earth ovens (umu ti) were used to cook Cordyline. Many earth ovens, from two to eight metres in diameter, still exist in southern New Zealand. A site surveying and excavation programme was carried out in South Canterbury to investigate these ovens. Radiocarbon dates on excavated ovens indicate that they were used throughout the prehistoric period of Maori occupation in South Canterbury. The construction of these ovens revealed through archaeological investigations was found to be identical with ethnographic descriptions. Residue analyses on soil from large raised-rim ovens indicate they were used for cooking Cordyline australis (the commonest species of Cordyline in New Zealand). Insect remains excavated from ovens point to a late spring to autumn use for cooking. I A thermoluminescence (TL) dating method using quartz inclusions from greywacke ovenstones was developed. A description of the equipment is given. Problems of dosimetry and measurement of TL is discussed and a recommended method of TL dating ovenstones is presented. TL dates and C-14 dates from the same ovens are compared. A nutritional study of Cordyline was undertaken. Complete proximate analyses of C. australis plants collected over a one year period were done. Maximum carbohydrate levels in the stems of C. australis occurred in late spring. This time is coincident with the recorded times of harvesting by Maori. Ti was found to be a rich source of carbohydrates, mainly fructose with some glucose from a glucofructofuranan type of polysaccharide. This polysaccharide required long cooking times (~24 hours) to convert it to edible sugars. Research points to Cordyline being a useful and important plant throughout Polynesia and especially in southern New Zealand.
Advisor: Anderson, Atholl
Degree Name: Doctor of Philosophy
Degree Discipline: Anthropology
Publisher: University of Otago
Research Type: Thesis