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ABSTRACTIn 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 ericoidesinto 10 species, it and K. sinclairiiwere 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 Kunzeaspecies from South Island and southern North Island. The SNP study confirms the microsatellite findings: the two widespread species, K. robustaand 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 Kunzearevision, 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.

ABSTRACTThe generic placement of the enigmatic and extinct Logania depressafrom 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 depressais 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 Geniostomahas been considered and its affinities to Oriantheraare unknown. Oriantherahas been recently recognised as a segregate of Logania. Using leaf material from a small fragment of L. depressaheld in Allan Herbarium (CHR) we recovered 9,368 bp of plastid sequence data that mapped to Mitreola yangchuensis, with Mitreolabeing the closest generic relative of Loganiafor 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. depressaas the only New Zealand member of Loganiasens. str., but its relationships to Australian species are unresolved.

ABSTRACTFour shrub species, including the newly described Pachystegia hesperiaHeenan & Molloy, are recognised in PachystegiaCheeseman, a genus endemic to southern Marlborough and northern Canterbury, South Island, New Zealand. Pachystegia hesperiais 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 hesperiahas 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. rufaMolloy are retained. Pachystegia insignishas 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 minoris 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 rufais distinguished by reddish trichomes on the leaves, stems and infloresences and has a restricted distribution in Haldon Hills, Marlborough. The widespread P. insignishybridises with P. minorand P. rufa. Typification, distribution, habitats and conservation status are presented for each species.

ABSTRACTTradescantia fluminensisVell. 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 fluminensiscomprises 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. fluminensisin Australia and South Africa are genetically more variable than in New Zealand. Two other entities, T. mundulaKunth (syn. T. albiflorahort.) and T. umbraculiferaHand-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 mundulaand T. umbraculiferashare a similar genome size and chromosome numbers (2n = 66, 68, 70 and 2C = 14.9 picograms), whereas T. fluminensishad lower values (2n = 56, 58; 2C = 11.7 picograms). Self-pollinations of T. fluminensisand T. umbraculiferafailed to produce seed, confirming that these two taxa are self-incompatible. Tradescantia mundulais self-compatible as the majority (93%) of self-pollinations produced fruit. Tradescantia umbraculiferaproduced 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 fluminensispollinated with T. mundulaor T. umbraculiferafailed to produce fruit or seeds. Self-incompatibility and failure to set seed when cross-pollinated with other species suggests the invasive T. fluminensisdoes not pose a threat of seedling establishment in indigenous ecosystems and vegetative spread remains the main method of reproduction and invasion.

ABSTRACTWe analysed nine microsatellite markers for 260 individuals representing Sophora tomentosaand 15 species from across the geographic range of Sophorasect. Edwardsia. The purpose of the study was to characterise the Sophoraspecies from Pacific Ocean islands and South America and determine their relationships to the eight New Zealand species, with relationships of the extinct Rapa Nui/Easter Island S. toromiroa particular focus. Structure, PCoA and NeighborNet analyses showed S. tomentosawas distinct from species of sect. Edwardsia. Among the species of sect. Edwardsia, S. cassioides, S. howinsula, S. longicarinata, S. prostrataand S. toromirowere genetically distinct as each comprised a high proportion of membership of individuals assigned to them. The remaining species were assigned to four genetic groups, each of which had one species with a high proportion of membership and other species with lower proportions of membership. The S. chrysophyllagroup also included high proportions of S. macrocarpa, S. denudataand S. raivavaeensis. The S. fulvida, S. godleyiand S. molloyigenetic groups mostly included low proportions of other New Zealand species. In the PCoA, S. toromirospecimens clustered together and were placed at the margin of a large sect. Edwardsiagroup. Sophora toromirocomprised four specimens representing the Melbourne Botanic Gardens (Australia) genotype and two specimens in the Allan Herbarium (CHR) obtained from cultivated specimens in Valparaíso (Chile) during the early 1970s. One specimen from Valparaíso was originally identified as S. toromiro, while the other was misidentified as Sophora macnabiana(now S. cassioides). The lack of genetic variation in S. toromirosuggests they were perhaps derived from the last surviving tree on Rapa Nui / Easter Island. A cultivated plant from New Zealand known as the ‘Victoria Park toromiro’ had its identity confirmed as S. godleyi, which is consistent with its morphological identification.

ABSTRACTThe 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-idaeaRaoul is lectotypified by a Raoul specimen in Muséum National d’Histoire Naturelle (P). This lectotype specimen is conspecific with the type specimen of Myrtus pedunculataHook.f. The publication date for Myrtus pedunculataHook.f. is January 1844 and that for Eugenia vitis-idaeaRaoul is August 1844. Therefore, Myrtus pedunculatahas priority, and the final epithet pedunculatain combination with Neomyrtusprovides Neomyrtus pedunculata(Hook.f.) Allan as the correct name for the species. Eugenia vitis-idaeaRaoul and Neomyrtus vitis-idaea(Raoul) Burret are treated as heterotypic synonyms of Neomyrtus pedunculata(Hook.f.) Allan.

ABSTRACTIndigenous 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.

ABSTRACTThree 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.

ABSTRACTPast studies of Sophorasect. Edwardsiausing traditional phylogenetic and population genetic markers have been unable to produce a resolved species phylogeny of this recent radiation of shrubs and trees. Here we examined the relationships within and between the New Zealand species of Sophorasect. Edwardsiausing next-generation sequencing. We generated genome-wide SNP data with double-digest restriction site-associated DNA sequencing (ddRADseq). Sophora prostratawas resolved as sister to the remaining species in all analyses. Relationships between the remaining taxa exhibited a high level of conflict with many of the genetic clusters reflecting geography rather than species boundaries. This result contrasts with a previous study, which was able to differentiate most species using genotype data from nine microsatellite loci. Overall our ddRADseq results indicate a high level of interspecific hybridisation and introgression within the group, which blurs the taxonomic boundaries throughout the distributional ranges of most species. Hybridisation and introgression among regional metapopulations comprising closely related species may increase the adaptive potential to respond to changing local conditions, and at the same time selection acts to maintain their genetic identity in the face of ongoing gene flow.

ABSTRACTTetragonia trigynaBanks & 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. trigynato synonymy of the Australian T. implexicoma(Miq.) Hook.f.. This was followed in 1999 by the first acceptance of T. implexicomain 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. implexicomahas become widely used in New Zealand. The taxonomic study of T. implexicomaand T. trigynareported here provides empirical data from herbarium specimens and cultivated plants, and concludes both species should be recognised. Tetragonia trigynadiffers from T. implexicomaby 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. trigynais reinstated with a distribution of New Zealand (including Chatham, Kermadec and Three Kings islands), Norfolk Island and Lord Howe Island, and T. implexicomais considered restricted to continental Australia and Tasmania.

ABSTRACTNeomyrtusis 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 pedunculatain a clade with the New Zealand endemic Lophomyrtus(subtribe Ugninae), comprising the two species L. bullataand 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 pedunculataand that it actually belongs to Lophomyrtus obcordata. We conducted a reanalysis of previously published data with new sequences from Neomyrtusand also undertook an analysis of 85 kbp of plastid protein coding genes from available Myrteae plastid genomes. These new phylogenetic analyses place Neomyrtusas sister to the New Caledonian endemic genus Myrtastrum, and the two species of Lophomyrtusform a clade that is sister to the Australian endemic Lenwebbia. Neomyrtusand Lophomyrtusare 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. Myrtastrumis currently treated as incertae sedisat subtribal rank, but along with Neomyrtuscould be considered as representing a new subtribe as our analyses suggest they are not part of any of the clades hitherto recognised as subtribes.

ABSTRACTKunzea(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 FSTand high allele migration (Nm). FSTvaried between 0.027 (K. robusta) and 0.084 (K. triregensis). The allopatric K. triregensisand K. salteraehad the highest difference in pairwise FSTat 0.155 and the sympatric K. robustaand K. serotinathe lowest at 0.005. Allele pairwise net migration (Nm) varied between 1.36 (K. triregensisand K. salterae) and 45.24 (K. robustaand K. serotina). The two most widespread species, K. robustaand 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 FSTand 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 Kunzeaspecies, 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.

ABSTRACTGingidiacomprises nine species of perennial herbaceous plants from New Zealand and three species from Australia. Microsatellite markers were developed for Gingidia enysiisens. lat. and G. baxteraefor 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. enysiisens. 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. enysiisens. lat. and G. baxteraethe 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. enysiisens. lat. to be naturally variable throughout its distributional range, and the suggested taxonomic novelties within G. enysiiare mostly not distinct. However, populations from Banks Peninsula (Canterbury), previously referred to as Gingidium enysiivar. 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.

ABSTRACTIt 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.

ABSTRACTA new species, Geranium cruentum, is described from New Zealand. Geranium cruentumis distinguished from G. brevicauleby 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 cruentumis 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.

ABSTRACTLineage through time plots (LTTs) are often used to explore past patterns of lineage diversification and community assembly. However, as they are based solely on extant species their ability to accurately depict past events can be questioned. Here, simulation models based on neutral processes are used to explore immigration and extinction scenarios to assist with interpretation of LTT plots generated from molecular clock age estimates for a nearly complete set of extant New Zealand vascular plant genera. With significant genus turnover, model simulations yield smooth exponential and linear semi-log LTT plots. Abrupt changes in extinction and immigration rates imposed in the scenarios caused only slight alterations of the curves. The vast majority of New Zealand vascular plant genera derive from trans-oceanic dispersal, and LTT plots generated from divergence dates and fossil data indicate consistently high turnover. Even major geological and climatic events leave minor signatures on LTT plots. Most notably, the maximum Oligocene Marine Transgression (27–22 Ma), when at least 85% of the current landmass was inundated, isn’t clearly registered. By themselves, LTT plots shed little light on the biotic effects of climatic or geomorphic change in the remote past and need to be interpreted in the light of fossil and geological data.

ABSTRACTThe New Zealand endemic and presumed extinct Stellaria elatinoidesHook.f. is shown to be conspecific with the Australian Stellaria multifloraHook. subsp. multifloraand 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 multiflorasubsp. multiflorais 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.

ABSTRACTA colonisation history for 411 extant genera and 477 lineages of the vascular flora of New Zealand was constructed using the plastid rbcLgene. 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.

ABSTRACTBrachyscome simplicifoliaJ.B.Armstr. was treated as incertae sedisby 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. simplicifoliais conspecific with Abrotanella linearisBerggr., and being the more recently published name is treated as a heterotypic synonym.

ABSTRACTNothofagaceae (southern beech) dominate two-thirds of the remaining indigenous forest of New Zealand. Four of the five species indigenous to New Zealand belong to the genus Fuscospora, and the remaining species to Lophozonia. Two species, Fuscospora cliffortioides(mountain beech) and Fuscospora solandri(black beech), are characterised by their small, entire leaves, characters not found in other species of the genus. Their taxonomic status and rank have been a persistent problem. While individuals of each species are often well differentiated by leaf shape and growth habit, intermediate plants and populations are common. They have been described as constituting a cline with morphological variation correlated with both elevation and latitude, and have been treated by many botanists as varieties of a single species. We assessed relatedness among populations of the two taxa by NeighborNet analysis and model-based inference of population structure using simple sequence repeat data. Two gene pools corresponding to the two taxa can be recognised, and these co-exist at a regional scale. The strongest correlations between environmental variables and membership of modelled populations corresponding broadly with mountain and black beech were with mean annual temperature, elevation, and longitude. Although past (and presumably ongoing) gene flow between them has occurred in areas of contact, the hybrid zone appears to be narrow, at least in some areas. It is appropriate to recognise these recently diverged taxa at species rank, despite local gene flow.

ABSTRACTFour shrub species, including three newly described, are recognised in the Melicytus obovatuscomplex from central New Zealand. The new species segregated from M. obovatussens. str. are M. improcerus, M. orariusand M. venosus, and are recognised based on a morphological assessment of growth habit, leaf and floral characters following detailed herbarium, cultivation and field studies. Melicytus obovatusis recircumscribed to include dioecious shrubs with leaves that are usually elliptic-oblong and the petals have a prominent purple margin. It occurs on a range of calcareous substrates in northwest Nelson, from near sea level to 944 m elevation. Melicytus improcerusalso occurs in northwest Nelson and is restricted to upper montane and subalpine zones between 800 and 1500 m elevation, predominantly on marble substrates. It has a low growing, compact growth habit, is dioecious, usually has leaves that are broadly elliptic-oblong, broadly elliptic or elliptic-oblong, and petals without a prominent purple margin. Melicytus orariusis a hermaphrodite shrub with obovate, broadly obovate or narrowly obovate leaves that have a distinctly retuse apex and the petals have a prominent purple margin. It is confined to coastal habitats in Cook Strait, and in the North Island is restricted to the Wellington region where it occurs from Kapiti Island in the west to the Wairarapa coast in the east, and in the South Island it occurs throughout the Marlborough Sounds. Melicytus venosusis only known to have female flowers and may be apomictic, and has broadly elliptic, broadly elliptic-oblong or ovate-orbicular leaves that have up to six teeth mostly in the distal half of the leaf margin. Its distribution is centred on the western Marlborough Sounds, with a disjunct population known from Kapiti Island. For each species, typification, description, distribution, habitats and illustrations are presented, along with an assessment of their conservation status.

ABSTRACTForty-four rhizobial isolates from New Zealand endemic Sophoraspecies growing in natural conditions were characterised and the effectiveness of selected isolates with regard to growth and N2fixation of different Sophoraspecies was tested. Sequences for the housekeeping genes (concatenated recA, gln11and rpoB) of the isolates were diverse but sequences for their symbiosis genes (nifHand nodC) were similar. Generally, isolates from the same field site showed similar housekeeping gene sequences. All isolates were Mesorhizobium. Twenty-six of the isolates aligned with Mesorhizobiumspecies previously isolated from New Zealand native Sophoraon the basis of their housekeeping gene sequences, but 18 isolates separated into two groups and a pair of isolates clearly separated from all Mesorhizobiumtype strains. DNA–DNA hybridisations indicated that isolates in the two groups could belong to two novel Mesorhizobiumspecies. Rhizobial isolates with different housekeeping gene sequences (but similar symbiosis gene sequences) gave similar increases in dry weight and total N content of four Sophoraspecies under glasshouse conditions.

ABSTRACTWe examined the phylogenetic relationships within Sophorasect. Edwardsiausing DNA sequences from the chloroplast trnQ-5′rps16and trnHGUG-psbAintergenic spacers and the nuclear-encoded chloroplast-expressed glutamine synthetase gene. Sequences were analysed with median-joining networks and phylogenetic approaches. Low sequence diversity was detected, which is consistent with past genetic studies of the section. Chloroplast and nuclear sequences are shared across large geographic distances. The New Zealand species did not form a monophyletic group, nor did the species from Chile. However, species on some Pacific Islands (Lord Howe Island, Easter Island, Hawaii and French Polynesia) and Réunion Island in the Indian Ocean appear to have unique chloroplast haplotypes, indicating isolation. The S. chrysophyllachloroplast haplotype derives from the French Polynesian haplotype rather than S. denudatafrom Réunion Island, with which it shares morphological characters. In the nuclear phylogeny Sophora macrocarpawas sister to the remaining species that were sequenced in the section, a relationship that has been previously suggested from morphological analysis.

ABSTRACTWe examined the origins of Sophoraseeds collected from the beaches of the Kermadec and Chatham Islands using chloroplast DNA sequencing and comparison with published sequences of known provenance. Sophoradoes not grow on the Kermadec Islands but two species grow on the Chatham Islands, both in low numbers. All seeds sequenced were confirmed to be from Sophorasect. Edwardsia. Several seeds exhibited novel DNA sequences that had not been found in past sampling. The remaining haplotypes have all been previously detected in the North and/or South Islands and some have also been recorded from Chile, Gough Island or the Juan Fernandez Islands. The two haplotypes that had been sequenced in the resident Chatham Islands S. chathamicapopulation were both found in the beach-cast seeds from the islands. However, an additional four haplotypes were also detected in the Chatham Islands beach-cast seeds, indicating dispersal from elsewhere.

Predicting survival and extinction scenarios for climate change requires an understanding of the present day ecological characteristics of species and future available habitats, but also the adaptive potential of species to cope with environmental change. Hybridization is one mechanism that could facilitate this. Here we report statistical evidence that the transfer of genetic information through hybridization is a feature of species from the plant genus Pachycladon that survived the Last Glacial Maximum in geographically separated alpine refugia in New Zealand’s South Island. We show that transferred glucosinolate hydrolysis genes also exhibit evidence of intra-locus recombination. Such gene exchange and recombination has the potential to alter the chemical defence in the offspring of hybridizing species. We use a mathematical model to show that when hybridization increases the adaptive potential of species, future biodiversity will be best protected by preserving closely related species that hybridize rather than by conserving distantly related species that are genetically isolated.

Sequence data from the internal transcribed spacer (ITS) nrDNA and rbcLcpDNA regions were used to determine relationships of genera of Brassicaceae from Australia and New Zealand (NZ) that were previously unassigned to a tribe. Maximum likelihood analysis of 71 ITS sequences identified a monophyletic clade of Australian genera, including Carinavalvaand Microlepidiumthat had previously been assigned to the tribe Microlepidieae. Pachycladonis not supported as monophyletic, comprising a clade of the NZ species and another clade of the Tasmanian P. radicatum.These two Pachycladonclades form a polytomy with the Australian clade. Maximum likelihood analysis of the rbcLregion generally supports the ITS analysis with the Australian genera forming a monophyletic clade with Pachycladon. Arabidellais polyphyletic in the rbcLphylogeny as A. eremigenais member of the Australian clade but A. trisectais 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 are Arabidella, Ballantinia, Blennodia, Carinavalva, Cuphonotus, Drabastrum, Geococcus, Harmsiodoxa, Irenepharsus, Menkea,Microlepidium, Pachycladon, Pachymitus,Phlegmatospermum, Scambopusand Stenopetalum.Whole­genome duplication has previously been shown to have occurred in the ancestry of Arabidella, Ballantinia, Pachycladonand Stenopetalumand 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.

The hypothesis that early plant radiations on islands dampen diversification and reduce habitat occupancy of later radiations via niche pre-emption has never, to our knowledge, been tested. We investigated clade-level dynamics in plant radiations in the alpine zone, New Zealand. Our aim was to determine whether radiations from older colonizations influenced diversification and community dominance of species from later colonizations within a common bioclimatic zone over the past ca10 Myr. We used stem ages derived from the phylogenies of 17 genera represented in alpine plant communities in the Murchison Mountains, Fiordland, and assessed their presence and cover in 262 (5 × 5 m) vegetation plots. Our results show clear age-related community assembly effects, whereby congenerics from older colonizing genera co-occur more frequently and with greater cover per unit area than those from younger colonizing genera. However, we find no evidence of increased species richness with age of colonization in the alpine zone. The data support priority effects via niche pre-emption among plant radiations influencing community assembly.

Austroderia turbaria Connor is a threatened grass endemic to the Chatham Islands. Although formerly more widespread, remaining natural populations consist of highly fragmented remnants and/or individuals. Population genetic analysis of seed-raised progeny from six of the extant natural populations on Chatham and Pitt islands, using amplified fragment length polymorphisms (AFLPs) and microsatellite markers, shows that there are very low levels of variation (expected estimated heterozygosity He 0.023–0.030, no. of effective alleles Na 1.039–1.053), and no significant differentiation within or between populations on the two islands. Flow cytometric analysis of endosperm to embryo ratios suggests a sexual breeding system. This lack of population variation and no discernable differences between the two islands suggest that management practices such as the establishment of new populations can be carried out irrespective of the location of source material. One caveat to this is the possibility of Fusarium wilt occurring on the islands, in which case measures should be taken to best prevent spread across the range of the species.

The article offers information on the discovery and description of plants in New Zealand. It provide insights on the recent taxonomic research, including conservation and biogeography, as well as the role of DNA data. Two taxonomic studies are presented, including of the conservation of Olearia adenocarpa, another is on the development of Pachycladon.