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Recent field surveys of the flora of Niue have identified three new species records for the island. Erigeron bellioides DC. (Asteraceae) and Psidium cattleyanum Sabine (Myrtaceae) are new naturalised records and Crepidomanes saxifragoides (C.Presl) P.S.Green (Hymenophyllaceae) is an addition to the indigenous flora. Crepidomanes is a new genus for the indigenous flora of Niue. Information is provided for each of these species on their biostatus, collections, distribution and habitats. Erigeron bellioides is known from several locations that provide access to sea and chasm walks where it mostly occupies disturbed and grassy habitats used for car parks. It is most probably being spread by seeds adhering to tourists’ footwear and vehicle tyres as they move between popular attractions. In contrast, Psidium cattleyanum is known from a single plant on the margin of regenerating secondary forest along the Puluhiki Sea Track (Lakepa). It is unlikely to have been planted at this site and may be cultivated in the nearby Lakepa village, which could be the seed source for the established wild plant. Psidium cattleyanum is an invasive species on other Pacific Islands and we recommend removal of the single known plant and survey for it elsewhere, including gardens of the villages. Crepidomanes saxifragoides is known from a single collection in primary forest of the Huvalu Forest Conservation Area where it grew on the shaded and moist surface of a root buttress at the base of a trunk of Syzygium. [ABSTRACT FROM AUTHOR]

In vascular plant systematics there are sometimes conflicts between phenotypic and ecotypic variation and genetic differentiation that challenge species concepts, introduce taxonomic confusion, and create nomenclatural uncertainty. Until a 2014 taxonomic revision that segregated Kunzea ericoides into 10 species, it and K. sinclairii were the only species recognised in New Zealand. A recent DNA microsatellite study failed to support any of the new species, instead revealing biogeographic variation. Here we present the results of a genotyping by sequencing study with 1,361 single nucleotide polymorphisms (SNPs), sampling 48 populations representing four Kunzea species from South Island and southern North Island. The SNP study confirms the microsatellite findings: the two widespread species, K. robusta and K. serotina, are indistinguishable and share northern and southern genotypes with other species; a single metapopulation lineage reflects a national north-to-south clinal pattern; and population differentiation is low and net migration high. A significant isolation by distance pattern was revealed with SNPs. The 2014 revision was explicitly based on the unified species concept, but the primary criterion, that each species represents a separate metapopulation lineage, was not demonstrated. Species recognition was based on morphological and ecological criteria that have proved difficult to apply. Applying the unified species concept and the primary criterion of a single metapopulation genetic lineage, we now recognise just a single New Zealand species, K. ericoides, with other species constituting taxonomic synonyms. In doing so, we distinguish a grey zone of taxonomic uncertainty that reflects incomplete lineage sorting, gene flow coupled with a lack of reproductive isolation, and only partial ecotypic and phenotypic differentiation. As demonstrated in the Kunzea revision, there is considerable phenotypic and ecotypic variation in regional populations that is likely to be of ecological and conservation importance. We suggest informal ecotypes are a better way to recognise this level of variation. [ABSTRACT FROM AUTHOR]