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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]

Taxonomic names at the rank of variety are often poorly understood and may be misapplied as their taxonomic circumscriptions can be inadequate. These names often fall out of favour or are neglected until they are eventually abandoned, but uncertainty can remain as to their taxonomic or nomenclatural status. While many variety names persist in the New Zealand flora literature and databases, unlike naming a new taxon there are no formal rules or guidelines for not accepting a name and placing it in synonymy. The taxonomic recognition of four varietal names accepted in the Flora of New Zealand Volume 1 (Allan 1961) are assessed against the species to which they are assigned to determine if they warrant continued recognition. These varietal names are Brachyglottis bidwillii var. viridis (Kirk) B.Nord. (Asteraceae), Corokia buddleioides var. linearis Cheeseman (Argophyllaceae), Mida salicifolia var. myrtifolia (A.Cunn.) Allan (Nanodeaceae) and Teucridium parvifolium var. luxurians Cheeseman (Labiatae). For each of these taxa, and the species to which they were assigned, the key characters circumscribing them were analysed. Each of the four varieties are not significantly different from the species to which they have been assigned and are therefore treated as synonyms. While the means of the type species and variety are different, this is not surprising as typically the variety is named for plants that have particularly wide or narrow leaves that mostly occur in a particular part of the range of phenotypic variation. Scatter plots confirm the leaf variation is continuous with no discrete groups. Discriminant analyses demonstrate that specimens were correctly named in only a relatively low percentage of cases, suggesting the measurement ranges are insufficient for reliable recognition and indicative of overlap between the two taxa. Accepted names are listed and a full synonymy is provided, including where necessary the typification of names. [ABSTRACT FROM AUTHOR]

The generic placement of the enigmatic and extinct Logania depressa from New Zealand has been uncertain due to the paucity of available plant material. This diminutive plant has only been collected once from the central North Island, New Zealand, by William Colenso on 22 February 1847. Logania depressa is dioecious and the single collection comprises only male flowers and does not include female flowers or fruit that feature generic diagnostic characters. Previously its relationship to Geniostoma has been considered and its affinities to Orianthera are unknown. Orianthera has been recently recognised as a segregate of Logania. Using leaf material from a small fragment of L. depressa held in Allan Herbarium (CHR) we recovered 9,368 bp of plastid sequence data that mapped to Mitreola yangchuensis, with Mitreola being the closest generic relative of Logania for which whole genome data was available. Available genetic data for Loganiaceae is limited to several chloroplast markers, including the rps16 intron, petD intron, and petD–petB intergenic spacer. From the novel plastid sequence data for Logania depressa, 48 bp of the rps16 intron, 45 bp of the petD intron and 49 bp of the petD–petB intergenic spacer could be recovered to compare with available Loganiaceae sequences. Phylogenetic analysis of these sequences confirmed L. depressa as the only New Zealand member of Logania sens. str., but its relationships to Australian species are unresolved. [ABSTRACT FROM AUTHOR]

Four shrub species, including the newly described Pachystegia hesperia Heenan & Molloy, are recognised in Pachystegia Cheeseman, a genus endemic to southern Marlborough and northern Canterbury, South Island, New Zealand. Pachystegia hesperia is distinguished by its compact and low statured growth habit, obovate to elliptic-oblong leaves with the adaxial surface reticulate with distinctive primary and secondary veins, a short peduncle and narrow capitula, smaller and fewer ray petals and fewer disc florets. It was previously known by the tagnames P. "B" or P. "Lowry". Pachystegia hesperia has a western and inland distribution comprising Lowry Peaks Range, Amuri Range, and southern parts of Inland and Seaward Kaikōura Ranges. The previously recognised P. insignis (Hook.f.) Cheeseman, P. minor (Cheeseman) Molloy and P. rufa Molloy are retained. Pachystegia insignis has the most widespread distribution and includes plants referred to the tagnames P. "A" or P. "Coast" and is naturally variable in leaf shape, capitula diameter and the presence and number of leafy bracts on the peduncle. Pachystegia minor is restricted to coastal and lowland habitats between Puhi Puhi and Waiau Toa / Clarence Rivers and includes plants from Ōhau Point (Marlborough) previously known by the tagname P. "C var. ii" or P. "Ōhau Point". It is distinguished by rhomboid to obovate leaves, narrow capitula and in having the fewest florets. Pachystegia rufa is distinguished by reddish trichomes on the leaves, stems and infloresences and has a restricted distribution in Haldon Hills, Marlborough. The widespread P. insignis hybridises with P. minor and P. rufa. Typification, distribution, habitats and conservation status are presented for each species. [ABSTRACT FROM AUTHOR]

Tradescantia fluminensis Vell. is an invasive species in Australia, New Zealand and South Africa. To assist biocontrol initiatives and management of the species we examine genetic variation in these countries and compare this to samples collected from its natural range in Brazil. Tradescantia fluminensis comprises two genetic groupings in New Zealand, both of which are shared with Australia and South Africa. One of these genotypes is relatively common in New Zealand and this is also shared with a Brazilian population. Populations of T. fluminensis in Australia and South Africa are genetically more variable than in New Zealand. Two other entities, T. mundula Kunth (syn. T. albiflora hort.) and T. umbraculifera Hand-Mazz. (syn. T. aff. fluminensis "Big"), new names for naturalised species in New Zealand, also comprise distinct genetic groups. These genetic data emphasise the importance of correct taxonomic identification of weed species being considered for biological control programmes. Tradescantia mundula and T. umbraculifera share a similar genome size and chromosome numbers (2n = 66, 68, 70 and 2C = 14.9 picograms), whereas T. fluminensis had lower values (2n = 56, 58; 2C = 11.7 picograms). Self-pollinations of T. fluminensis and T. umbraculifera failed to produce seed, confirming that these two taxa are self-incompatible. Tradescantia mundula is self-compatible as the majority (93%) of self-pollinations produced fruit. Tradescantia umbraculifera produced a low number of fruit and seeds per fruit when pollinated by T. mundula, but no fruit or seeds were formed when it was pollinated by T. fluminensis. Tradescantia fluminensis pollinated with T. mundula or T. umbraculifera failed to produce fruit or seeds. Self-incompatibility and failure to set seed when cross-pollinated with other species suggests the invasive T. fluminensis does not pose a threat of seedling establishment in indigenous ecosystems and vegetative spread remains the main method of reproduction and invasion. [ABSTRACT FROM AUTHOR]

The generic relationships of the extinct Trilepidea adamsii (Cheeseman) Tiegh. from New Zealand have been uncertain due to the paucity and age of available plant material. Last seen nearly seventy years ago in 1954, fresh material has not been available for comparative studies. Trilepidea adamsii has morphological affinities to Alepis flavida (Hook.f.) Tiegh., Peraxilla colensoi (Hook.f.) Tiegh. and P. tetrapetala (L.f.) Tiegh. with all taxa being placed in subtribe Elytranthinae, but precise phylogenetic relationships have not been determined. Using leaf material of Trilepidea adamsii from a specimen in Allan Herbarium (CHR) collected in 1920 from near Thames, Coromandel Peninsula, North Island, we recovered approximately 93% of the plastid genome by mapping Illumina sequence reads to a plastid genome sequence of Elytranthe albida (Blume) Blume, with Elytranthe being another genus of Loranthaceae. We also sequenced plastid genomes of Alepis flavida, Peraxilla colensoi and Peraxilla tetrapetala and conducted a phylogenetic analysis using other Loranthaceae plastid genome sequences from GenBank. Phylogenetic analyses of the plastid genome sequences confirmed T. adamsii as sister to a clade comprising Alepis and Peraxilla. While the level of sequence divergence is low, we do not consider that the generic boundaries need to be reassessed. We suggest re-examination of anatomical and morphological traits is warranted to better understand evolution in this lineage of four endemic mistletoe species. [ABSTRACT FROM AUTHOR]

Indigenous plant naming systems and systematic botanical nomenclature involve different methodologies that result in different knowledge systems. Botanical nomenclature provides a single, universal name for a plant based on its taxonomic and evolutionary relationships. Indigenous classifications allow ready identification of plants for particular communities sharing a common language and cultural milieu to which the names are specific. The two systems are independent, but they can profit from mutual comparison, and each should be respected and valued for its distinctive role. A recent proposal argues that indigenous vernacular plant names, being older than those given in colonial circumstances, should have priority over existing botanical names. This suggestion, along with the call for greater use of indigenous languages in specific epithets, is here discussed in relation to the New Zealand flora. We conclude that the proposal would require extensive, complex changes to the International Code of Nomenclature, result in nomenclatural instability, and subject indigenous names to the rules of botanical nomenclature while severing them from their local cultural contexts. We suggest the proposal undermines indigenous naming systems, threatens the integrity of indigenous languages, and would disrupt botanical nomenclature for little benefit. [ABSTRACT FROM AUTHOR]

The type specimen and date of publication of the basionym for each of Neomyrtus pedunculata (Hook.f.) Allan and its synonym Neomyrtus vitis-idaea (Raoul) Burret are clarified to establish that the correct nomenclature is being used. Eugenia vitis-idaea Raoul is lectotypified by a Raoul specimen in Muséum National d'Histoire Naturelle (P). This lectotype specimen is conspecific with the type specimen of Myrtus pedunculata Hook.f. The publication date for Myrtus pedunculata Hook.f. is January 1844 and that for Eugenia vitis-idaea Raoul is August 1844. Therefore, Myrtus pedunculata has priority, and the final epithet pedunculata in combination with Neomyrtus provides Neomyrtus pedunculata (Hook.f.) Allan as the correct name for the species. Eugenia vitis-idaea Raoul and Neomyrtus vitis-idaea (Raoul) Burret are treated as heterotypic synonyms of Neomyrtus pedunculata (Hook.f.) Allan. [ABSTRACT FROM AUTHOR]

Three naming systems have been applied to the flora of Aotearoa New Zealand, but differences in their use are poorly understood. Analyses of 45 sets of Māori and settlers' vernacular plant names and botanical names in Papers Past between 1839 and 1948 shows that Māori plant names were well-used in referring to the flora. Māori plant names (2,242,201; 82.6%) are mentioned more than settlers' names (465,155; 17.1%) or botanical nomenclature (8,193; 0.3%). Māori name usage was dominant from 1839 to 1858, declined during 1859–1868 when settlers' names were featured, and increased from 53.15% in 1869 to 90.89% in 1948. In Papers Past, 32 (71.0%) of the 45 Māori plant name(s) are mentioned most often, followed by 11 (24.5%) settlers' and two (4.5%) botanical names. Analysis of the 45 sets of names in four New Zealand science journals (1863–2020) shows the number of name mentions to be: botanical nomenclature 10,827 (54.4%), Māori 6,731 (33.8%) and settlers' 2,341 (11.8%). Botanical nomenclature (35 names) and Māori names (10 names) were the most mentioned of the 45 sets of names in the science journals. Analysis of the 45 sets of names in a Google Search undertaken in 2021 confirmed the prevalence of Māori names (92.5%) over botanical nomenclature (7.5%). The most mentioned Māori names refer to plants of economic importance such as rimu, mānuka and mataī. The overall dominance of Māori plant name mentions does not support recent contentions that botanical nomenclature has 'set aside' and 'replaced' these. Further, the low number of total mentions of botanical nomenclature in Papers Past and the science journals suggests little is to be gained from promoting the use of Māori epithets in botanical nomenclature for newly named taxa, and a strategy for the promotion of Māori plant names in the context of indigenous ecological knowledge is perhaps desirable. [ABSTRACT FROM AUTHOR]

Neomyrtus is a New Zealand endemic monotypic genus that has been assigned to the Myrtaceae tribe Myrteae. Previous phylogenetic studies using the five genetic markers ITS, ETS, matK, psbA-trnH, and rpl16 have placed the single species Neomyrtus pedunculata in a clade with the New Zealand endemic Lophomyrtus (subtribe Ugninae), comprising the two species L. bullata and L. obcordata. Examination of the single herbarium voucher (OTA 57310) representing the plant material from which the DNA for the five phylogenetic markers was obtained revealed that it had been misidentified as Neomyrtus pedunculata and that it actually belongs to Lophomyrtus obcordata. We conducted a reanalysis of previously published data with new sequences from Neomyrtus and also undertook an analysis of 85 kbp of plastid protein coding genes from available Myrteae plastid genomes. These new phylogenetic analyses place Neomyrtus as sister to the New Caledonian endemic genus Myrtastrum, and the two species of Lophomyrtus form a clade that is sister to the Australian endemic Lenwebbia. Neomyrtus and Lophomyrtus are not closely related within the context of the tribe. This change to the understanding of Myrteae phylogeny is discussed in terms of available morphological character data and the biogeography of the tribe. Myrtastrum is currently treated as incertae sedis at subtribal rank, but along with Neomyrtus could be considered as representing a new subtribe as our analyses suggest they are not part of any of the clades hitherto recognised as subtribes. [ABSTRACT FROM AUTHOR]

Tetragonia trigyna Banks & Sol. ex Hook.f. was the accepted name for a well-known coastal species in New Zealand from when it was formally named by J. D. Hooker in 1864 until the 1990s. In 1994, a Flora of Australia volume covering Norfolk and Lord Howe Islands reduced T. trigyna to synonymy of the Australian T. implexicoma (Miq.) Hook.f.. This was followed in 1999 by the first acceptance of T. implexicoma in New Zealand botanical literature when the name was used in a checklist of plant species from Aorangi Island, Poor Knights Islands. In a departure from what is generally considered accepted taxonomic practice, no empirical evidence or discussion of characters was provided in support of either decision. Subsequently, T. implexicoma has become widely used in New Zealand. The taxonomic study of T. implexicoma and T. trigyna reported here provides empirical data from herbarium specimens and cultivated plants, and concludes both species should be recognised. Tetragonia trigyna differs from T. implexicoma by its broader leaves, shorter pedicels, shorter tepals, and fewer and shorter stamens. Images in the citizen science iNaturalist platform confirm the diagnostic characters and distribution, and recently published nrDNA ITS sequence data distinguish both species. Accordingly, T. trigyna is reinstated with a distribution of New Zealand (including Chatham, Kermadec and Three Kings islands), Norfolk Island and Lord Howe Island, and T. implexicoma is considered restricted to continental Australia and Tasmania. [ABSTRACT FROM AUTHOR]

Phylogenetic diversity analyses were used to interpret the timing and assembly of vegetation communities in temperate New Zealand. A data set comprising 1638 permanent vegetation plots provided plant-distributional data, and a plastid rbcL phylogenetic tree provided phylogenetic metrics. Mean crown age, standardized effect size of mean pairwise distance and standardized effect size of mean nearest taxon distance were analysed in relation to taxonomic groups (angiosperms, gymnosperms and pteridophytes), life form (woody angiosperms, non-woody angiosperms) and temperature and precipitation using generalized additive models. Angiosperms in South Island have a younger crown age than those in most North Island sites, and phylogenetic clustering is prevalent throughout. Angiosperms and pteridophytes from drier and cooler open-habitat communities in central and eastern South Island have younger crown ages and phylogenetic clustering compared to wetter and warmer closed-habitat communities of western South Island and North Island, with older crown ages and phylogenetic over-dispersion. Phylogenetic clustering is consistent with species-rich radiations that have diversified into newly available niches during the late Miocene to Plio-Pleistocene. Pteridophytes displayed less phylogenetic relatedness than angiosperms, reflecting their older crown ages. These findings are consistent with a view that northern New Zealand retained older lineages of subtropical origin during glaciations, whereas novel habitats in cool, dry climates in southern New Zealand facilitated more recent radiations. These results emphasize the strong legacy of history in the modern-day composition of plant communities. [ABSTRACT FROM AUTHOR]

Kunzea (kānuka) in New Zealand comprises ten endemic species following a recent taxonomic revision, several of which are abundant, widespread and ecologically important as early successional colonisers. The species are difficult to recognise in the field in many areas, some plants appear intermediate between species and it has been argued hybrids are common. Microsatellite markers are used to investigate genetic variation in these ten species. The species are only weakly supported as they are characterised by low differentiation as reported by FST and high allele migration (Nm). FST varied between 0.027 (K. robusta) and 0.084 (K. triregensis). The allopatric K. triregensis and K. salterae had the highest difference in pairwise FST at 0.155 and the sympatric K. robusta and K. serotina the lowest at 0.005. Allele pairwise net migration (Nm) varied between 1.36 (K. triregensis and K. salterae) and 45.24 (K. robusta and K. serotina). The two most widespread species, K. robusta and K. serotina, are genetically indistinguishable and share northern and southern genotypic clusters. Six species or groups of species are recognised in the Structure analysis but these too are characterised by low FST and high allele migration (Nm). Four genotypic clusters shown by Structure analysis are distributed along a north to south latitudinal gradient cutting across species boundaries and corresponding with established biogeographic regions of New Zealand. This provides the strongest pattern of genotypic variation in the study. The weak level of genetic support for the ten Kunzea species, lack of breeding barriers between them, and problems in recognising some of the species in the field, raises questions as to their validity. However, given the ecological, conservation and economic importance of Kunzea, the ten species currently circumscribed should be retained until decisions are made as to how to recognise the variation within the species complex. [ABSTRACT FROM AUTHOR]

Gingidia comprises nine species of perennial herbaceous plants from New Zealand and three species from Australia. Microsatellite markers were developed for Gingidia enysii sens. lat. and G. baxterae for genetic and systematic studies of the two species in New Zealand. From sequencing a total genomic DNA library (using Roche 454), we developed nine polymorphic microsatellite markers. We tested these markers on 142 individuals from 19 populations of G. enysii sens. lat. and 10 individuals from two populations of G. baxterae. All loci amplified in both species, and exhibited species-specific alleles. In populations of G. enysii sens. lat. and G. baxterae the observed and expected heterozygosities ranged from 0.04–0.34 and from 0.31–0.80, respectively, with alleles per locus ranging from 7 to 25. Analyses of population genetic data show G. enysii sens. lat. to be naturally variable throughout its distributional range, and the suggested taxonomic novelties within G. enysii are mostly not distinct. However, populations from Banks Peninsula (Canterbury), previously referred to as Gingidium enysii var. peninsulare, are genetically discrete, and re-examination of their morphological characters is warranted. The developed markers will be valuable for future studies of taxonomy, phylogenetics, population structure, and mating system. [ABSTRACT FROM AUTHOR]

A new species, Geranium cruentum, is described from New Zealand. Geranium cruentum is distinguished from G. brevicaule by its dark green leaves, broadly elliptic to obovate primary lobes with a deep sinus between the lobes, fewer secondary lobes, conspicuous dark reddish purple-brown blotches, and prominent leaf hair bases. Geranium cruentum is known from a single ostensibly wild collection made in 1993 from the Von River valley, Southland, and despite repeated searches has not been re-collected from the wild. It may be extinct in the wild but is cultivated in several gardens. As it persists ex situ in cultivation its conservation status is assessed as Threatened, Nationally Critical, using the New Zealand Threat Classification System. [ABSTRACT FROM AUTHOR]

The New Zealand endemic and presumed extinct Stellaria elatinoides Hook.f. is shown to be conspecific with the Australian Stellaria multiflora Hook. subsp. multiflora and is treated as a heterotypic synonym. A suite of morphological characters unifies these two taxa, including an annual growth habit, glabrous stems and leaves, sessile leaves, monochasial inflorescences, usually apetalous flowers, short styles and stamens, broadly ellipsoid capsule with valve apices strongly revolute, and the seeds suborbicular and with uniformly-sized prominent tubercles. The biostatus of Stellaria multiflora subsp. multiflora is reviewed and it is treated as indigenous to Australia and New Zealand, and since it was last collected from New Zealand in 1921 its conservation status there is confirmed as extinct. [ABSTRACT FROM AUTHOR]

A colonisation history for 411 extant genera and 477 lineages of the vascular flora of New Zealand was constructed using the plastid rbcL gene. Molecular clock crown ages suggest that the Eocene-Oligocene transition extinction at 33.9 Ma was critical to the development of the extant flora as few lineages, mostly ferns and conifers, predate this event. Based on crown dates, almost all extant angiosperm lineages have established after the Eocene-Oligocene transition extinction. The Oligocene marine transgression had little discernible impact on the formation of the extant flora, as at the culmination of the inundation (22.0–25.0 Ma) fifty extant lineages of vascular plant were present and another eight lineages originated during this time. The majority of extant species (89%) originated after the end of the Miocene Thermal Optimum at about 15.0 Ma. Nearly 50% of the extant species have evolved during mountain uplift and glaciation of the late Pliocene-Pleistocene (0–4.99 Ma). Therefore, despite a residual contribution from the Eocene, Oligocene and early to mid Miocene periods, the New Zealand vascular flora essentially originated in the late Miocene and after. [ABSTRACT FROM AUTHOR]

Brachyscome simplicifolia J.B.Armstr. was treated as incertae sedis by H.H. Allan in the Flora of New Zealand, Volume 1, published in 1961. At that time, H.H. Allan, along with the earlier flora writers T. Kirk and T.F. Cheeseman, had not seen herbarium material referable to that name. An authentic herbarium specimen from the Armstrong Herbarium, formally part of the Christchurch Botanic Gardens Herbarium (CHBG) but now housed at the Allan Herbarium (CHR), has been located and is designated as lectotype for B. simplicifolia. Based on this lectotypification, B. simplicifolia is conspecific with Abrotanella linearis Berggr., and being the more recently published name is treated as a heterotypic synonym. [ABSTRACT FROM AUTHOR]

Sequence data from the internal transcribed spacer (ITS) nrDNA and rbcL cpDNA regions were used to determine relationships of genera of Brassicaceae from Australia and New Zealand (NZ) that were previously unassigned to a tribe. Maxi-mum likelihood analysis of 71 ITS sequences identified a monophyletic clade of Australian genera, including Carinavalva and Microlepidium that had previously been assigned to the tribe Microlepidieae. Pachycladon is not supported as monophyletic, comprising a clade of the NZ species and another clade of the Tasmanian P. radicatum. These two Pachycladon clades form a polytomy with the Australian clade. Maximum likelihood analysis of the rbcL region generally supports the ITS analysis with the Australian genera forming a monophyletic clade with Pachycladon. Arabidella is polyphyletic in the rbcL phylogeny as A. eremigena is member of the Australian clade but A. trisecta is placed in a sister clade that comprises mainly genera of tribe Camelineae. As a result of these phylogenetic analyses the tribe Microlepidieae is expanded and now includes 16 genera and 56 species endemic to Australia and New Zealand. Genera included in the Microlepidieae axe Arabidella, Ballantinia, Blen-nodia, Carinavalva, Cuphonotus, Drabastrum, Geococcus, Harmsiodoxa, Irenepharsus, Menkea, Microlepidium, Pachycladon, Pachymitus, Phlegmatospermum, Scambopus and Stenopetalum. Whole-genome duplication has previously been shown to have occurred in the ancestry of Arabidella, Ballantinia, Pachycladon and Stenopetalum and is likely to be a defining feature of the tribe Microlepidieae. Future research needs to investigate circumscription of the Australian genera as there is a predominance of closely related monotypic genera in the Microlepidieae. With resolution of the tribal placement of these Australian and New Zealand genera, ca. 94% (302) of the 321 genera in the family have been assigned to a tribe. [ABSTRACT FROM AUTHOR]