The Flora of Niuatoputapu Island, Tonga Pacific Plant Studies 32 Harold St. John Bishop Museum, Honolulu, Hawaii, 96818 Geography Niuatoputapu Island is almost at the northern end of the Tongan chain and is very close to Samoa (140 miles to Upolu Island) . Its closest neighbors are the volcanic ash cone of Tafahi, only 5 miles to the north, and Niuafo'ou (Tin Can) Island, some 120 miles to the west. Niuatoputapu is of volcanic origin, with a cen-tral ridge of bedded tuff, breccia, and lavas which rises to a maximum height of 165 meters. Surrounding this central ridge is a terrace, probably wave-cut in origin and Pleistocene in age, now coverj^ed with a thick and fertile deposit of clay soils. Falling away in a relatively steep bluff, this terrace is in turn surrounded by an apron-like plain of uplifted recent marine sedi-ments: sand, coral cobbles, and other reef detri-tus. This apron of low-lying terrain has been uplifted as a result of tectonic activity within the period of Polynesian occupation of Niu£opu-tapu . The island is 6.8 kilometers long and 4.5 kilometers wide. The vegetation of Niuatoputapu has been exten-sively modified as a result of some 3,000 years of Polynesian occupation. The present Tongan-speaking population practices a form of shifting cultivation (or bush-fallow rotation) in which the principal garden type is the mixed yam-'aroid swidden (refer to P. V. Kirch, "Indigenous agri-culture in Uvea" in press, Economic Botany) for a description of a highly similar West Polynesian agricultural system. The principal cultivated yams are Dioscorea alata and D. esculenta ; among the cultivated aroids are Colocasia esculenta , Alocasia macrorrhiza , and Xanthosoma sagitti folium . Bananas, particularly diploid hybrids of the Musa section, are extensively planted in swiddens following the harvest of yams and aroids. Arboriculture also is a sig-37U
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