Te reo Māori and botanical nomenclature as complementary naming systems for New Zealand's flora

It is argued that the greater use of te reo Māori and ta re Moriori languages for naming new taxa in the flora of Aotearoa / New Zealand supports the aspirations of Māori and Te Tiriti o Waitangi. However, using these indigenous languages in botanical nomenclature is more complex than a simplistic 'more is better', and we identify a number of issues requiring consideration. We appraise Waitangi Tribunal claim Wai 262 and Te Tiriti o Waitangi, collaboration at the interface of mātauranga Māori and research science, debate whether iwi are active collaborators or informants, and, crucially, defend the credibility and utility of te reo Māori / ta re Moriori and botanical nomenclatural systems. We conclude that (1) formal botanical nomenclature and (2) te reo and ta re vernacular plant names are independent, complementary, and mutually supportive classifications, each with different purposes and denoting two functional knowledge systems. Our recommendation when naming new taxa is to derive names from botanical Latin terminology. To provide clarity for the application of indigenous languages in naming Aotearoa / New Zealand vascular plants and bryophytes, an assessment of the rules and recommendations in the International Code of Nomenclature (ICN) is presented, including the use of geographical, personal and plant vernacular names as epithets, diacritical signs, hyphens, combinations of different languages, and epithet authorship. For those considering using te reo or ta re names for a new taxon, we present guidelines that address dialogue between scientists and iwi, key aspects of the ICN to consider, and suggestions for maintaining the scientific credibility of nomenclatural practices. A knowledge gap is identified for ethnobotanical folk taxonomy research into vernacular te reo and ta re names, and to document and promote this mātauranga we recommend Māori-led research into etymology, hierarchical structure, cultural relationships, whakapapa, and relationships to botanical names.