This paper describes the toponymy of the Abui community of Eastern Indonesia (Papuan, Alor Archipelago). In absence of detailed cartographic documentation, we have built a database of Abui place names. The data was collected using various tasks (hiking, narratives, map-drawing and elicitation) and annotated in a database tracking the type of place name, its etymology, and the onomastic source. The paper demonstrates that the toponymic pattern in the Abui community is largely native, transparent, and derived from the agricultural and horticultural use of the landscape. The most prominent source of place names are tree names (both fruit and cash crop). In their swiddening practice, the Abui farmers promoted the growth of certain tree species and derived landmark names from them. These names provide evidence of the emergence of secondary forest, stimulated by the targeted harvesting of trees such as canarium or candlenut over the past centuries. The peripheral, coastal toponymic interface records traces of inter-island trade driven by the available cash crops. Finally, we report the social functions of place names. Place name sequences function as keychains, which affirm kin relations, stake out land claims and rights but also verify the truthfulness of certain ancestral myths. The paper shows that even in areas where detailed cartographic and historical data are absent, a great deal of information can be obtained from the systematic study of toponyms and their function in various types of discourse.