The transfer of kūmara (Ipomoea batatas) from East to South Polynesia and its dispersal in New Zealand

Whether kūmara ‘sweet potato’ (Ipomoea batatas) arrived in South Polynesia with initial colonisation or later is discussed in the light of recent evidence from East Polynesia and by examination and statistical modelling of radiocarbon ages associated with kūmara arrival and dispersal in New Zealand. Largely unresolved difficulties in radiocarbon dating of horticultural sites preclude reaching a secure conclusion about the relative timing of kūmara introduction, but strong evidence emerges of delayed dispersal southward and inland of kūmara cultivation. In the short New Zealand chronology this may have been more significant than the date of arrival for the role of kūmara cultivation in economic and political change.