P. B. Heenan

Threatened and uncommon plants of New Zealand

Abstract A reappraisal of the conservation status of the indigenous New Zealand vascular plant flora is presented. The list comprises 792 taxa (34% of New Zealands total indigenous vascular flora) in the following categories: Extinct 4 taxa, Acutely Threatened 122 taxa (comprising 47 taxa Nationally Critical, 54 Nationally Endangered, 21 Nationally Vulnerable), Chronically Threatened 96 taxa (comprising Serious Decline 26 taxa, Gradual Decline 70 taxa), At Risk 499 taxa (comprising Sparse 126 taxa, Range Restricted 373 taxa), Non‐resident Native 26 taxa (comprising Vagrant 16 taxa, Colonist 10 taxa), and Data Deficient 45 taxa. A further 208 plants are listed as Taxonomically Indeterminate, being those which might warrant further conservation attention once their taxonomic status is clarified. A further 31 named taxa and 18 rated as Taxonomically Indeterminate, and previously considered to be threatened and/or uncommon, are removed from this updated listing. A concordance of plant names is provided. The lists presented use a new threat classification system developed by the New Zealand Department of Conservation for sole use within this country. This paper represents the first time the entire known indigenous vascular flora has been assessed from a conservation perspective since the mid 1970s. A brief analysis of the patterns of rarity exhibited by the taxa listed is presented.

Threatened and uncommon plants of New Zealand (2008 revision)

Abstract A reappraisal of the conservation status of the indigenous New Zealand vascular plant flora is presented using the 2008 version of the threat classification system developed for the New Zealand Department of Conservation. The list comprises 897 taxa (38% of New Zealands total indigenous vascular flora) in the following categories: Extinct—6 taxa, Threatened—180 taxa (comprising 91 Nationally Critical taxa, 45 Nationally Endangered, and 44 Nationally Vulnerable), At Risk—651 taxa (comprising 83 Declining, 6 Recovering, 20 Relict, and 542 Naturally Uncommon taxa), 25 taxa listed as either Vagrant (12) or Coloniser (13), and 35 as Data Deficient. A further 171 plants are listed as taxonom ically indeterminate, being those which might warrant further conservation attention once their taxonomic status is clarified. Forty‐four recognised taxa and 26 plants rated as taxonomically indeterminate, and previously considered to be threatened and/or uncommon, are removed from this updated listing. A brief analysis of the patterns of rarity exhibited by the listed taxa is presented. Overall, the conservation status of the New Zealand indigenous vascular plant flora is worsening, with 7.6% of this flora now regarded as threatened with extinction. A concordance of plants names from the 2004 listing is provided.

Molecular systematics of the New Zealand Pachycladon (Brassicaceae) complex: generic circumscription and relationships to Arabidopsis sens. lat. and Arabis sens. lat.

Abstract Nuclear ribosomal DNA ITS sequence data were used to assess the relationships of Cheesemania, Ischnocarpus, and Pachycladon to each other and to other genera in the Brassicaceae. Phylogenetic analyses are congruent with other studies that infer the Pachycladon complex (including Pachycladon, Cheesemania, and Ischnocarpus) is monophyletic. The complex occurs within an Arabidopsoid clade that includes Arabidopsis and the recently recognised segregate genera Beringia, Crucihimalaya, Olimarabidopsis, and Pseudoarabidopsis, and the Arabis segregates Boechera and Turritis. The Pachycladon complex is sister to Beringia and Crucihimalaya, and forms a distinct New Zealand lineage. Molecular clock estimates suggest the Pachycladon complex diverged from its nearest relatives between 1.0 and 3.5 million years ago. The close relationship of Cheesemania, Ischnocarpus, and Pachycladon is reflected in low (<2.6%) sequence divergence values, high bootstrap support (98%), and the lack of a well‐resolved topology in the phylogenetic trees. Morphological characters and data from previous studies of intergeneric hybrids and DNA Amplified Fragment Length Polymorphisms, support the recircumscription of Pachycladon to include species placed in Cheesemania and Ischnocarpus. New combinations are made in Pachycladon for species previously placed in Cheesemania and Ischnocarpus. A new name, P. cheesemanii, is presented for Ischnocarpus novae‐zelandiae as that species epithet is preoccupied in Pachycladon.

Classification, origins, and patterns of diversification in New ZealandCarmichaelinae (Fabaceae)

Analysis of ITS sequences provides support for a clade that includes Carmichaelia, Clianthus, Montigena, and Swainsona. We provide a node-based definition and recommend that this clade be called Carmichaelinae. Results suggest that Carmichaelinae are derived from northern hemisphere Astragalinae. The clade has extensively radiated in Australia, and two independent lineages have diversified in New Zealand. The New Zealand lineages differ in species richness. One lineage consists of 24 species placed in Carmichaelia and Clianthus, while the other corresponds to the monotypic genus Montigena. The pattern of relationships inferred from ITS sequences suggests that the New Zealand radiation was recent and possibly accompanied episodes of mountain-building and glaciation.

Systematic Relationships of New Zealand Endemic Brassicaceae Inferred from nrDNA ITS Sequence Data

Abstract Phylogenetic relationships of New Zealand species of Brassicaceae belonging to the South Island endemic Ischnocarpus, Iti, Notothlaspi, and Pachycladon, and the indigenous Cardamine, Cheesemania, Lepidium, and Rorippa were studied using nuclear ribosomal internal transcribed spacer sequences. Results support a monophyletic Notothlaspi and suggest that species of this genus are not closely related to Thlaspi, the genus to which Hooker provisionally assigned N. australe. The cosmopolitan genus Cardamine is paraphyletic by the inclusion of the monotypic genus Iti. The association of Iti with New Zealand Cardamine is of particular significance, as the relationships of this monotypic genus have historically proven elusive. Cheesemania species, Ischnocarpus novae-zelandiae, and Pachycladon novae-zelandiae form a closely related monophyletic group. The species of Lepidium form a monophyletic group, but the New Zealand species are not monophyletic indicating two possible dispersal events to New Zealand. Additionally, the tribes Arabidieae, Lepidieae, and Sisymbrieae are polyphyletic. This study highlights the difficulty of using traditional characters such as fruit type and cotyledon arrangement to define the tribes of the Brassicaceae. Communicating Editor: John Freudenstein

Sophora (Fabaceae) in New Zealand: Taxonomy, distribution, and biogeography

Abstract A taxonomic treatment is provided for the Sophora microphylla complex in New Zealand. Sophora microphyllu sens. str. is endemic to New Zealand, and includes those plants with a distinct divaricating and/or strongly flexuose juvenile Phase, orange‐brown to Yellow‐brown Juvenile stems, and distant leaflets. S. chathamica is reinstated at species rank, S.fulvida is a new combination provided for the taxon previously known as S. microphylla Var. fulvida, and S. godleyi and S. molloyi are described as new species. S. chathamica, S. fulvida, S. godleyi and S. molloyi lack a divaricating and/or strongly flexuose juvenile phase and are each distinguished by a number of leaf characters. S. fulvida and S. godleyi have distinctive leaf hairs. S. chathamica is a predominantly coastal species in Northland, Auckland, Waikato, Wellington, and the Chatham Islands, S.fulvida occurs in Northland and North Auckland on volcanic rock outcrops S. godleyi Occurs on calcareous mudstone and sandstone in eastem Taranaki King country, Wanganui and Manawatu, and S. molloyi is restricted to extremely dry and exposed bluffs and rock outcrops of southern North Island headlands, Kapiti Island, and several islands in Cook Strait. Cluster analyses of 11 leaf and 4 growth habit characters provide additional support for the revised classification, and variation in 7 leaf characters is evaluated with box plots. A key is provided to Sophora in New Zealand, hybridism is discussed, an assessment of each species’ conservation status is made, and biogeography is reconsidered in view of the new taxonomic treatment.

A Pleistocene inter-tribal allopolyploidization event precedes the species radiation of Pachycladon (Brassicaceae) in New Zealand

The Southern Alps in New Zealand contain many herbaceous plant groups that have radiated during the Plicoene-Pleistocene. The species in these genera tend to be polyploid relative to their overseas close relatives, an observation of much interest given that hybridization and allopolyploidy have recently been suggested as a possible stimulus for adaptive radiation. We were interested to determine whether or not allopollyploidy was a feature of Pachycladon, a genus which is hypothesised to have adaptively diversified onto different geological substrates in the mountains of the South Island of New Zealand. Phylogenetic analyses of five single-copy nuclear genes show that Pachycladon species have two copies of each gene representing two highly diverged evolutionary lineages from the Brassicaceae. Molecular clock analyses of all loci suggest that the two genome copies in Pachycladon diverged 8 million years ago, and that the allopolyploid origin of the genus occurred during the Pleistocene between 1.6 and 0.8 million years ago. This hybridization event at the origin of the Pachycladon radiation is perhaps the most extreme example yet reported of successful hybridization between distantly related parents.

Checklist of dicotyledons, gymnosperms, and pteridophytes naturalised or casual in New Zealand: Additional records 1997–1998

Abstract New records of fully naturalised and casual plants are reported for the flora of New Zealand during the 3‐year period 2001–2003. Ten species are reported as additional or newly substantiated fully naturalised, 92 taxa are considered to be new records of casual plants, and 13 additional species that were previously known from few collections are given extended distributions.

Hybridization may facilitate in situ survival of endemic species through periods of climate change

Predicting species’ chances of survival under climate change requires an understanding of their adaptive potential. Now research into hybridization—one mechanism that could facilitate adaptation—shows that species of the plant genus Pachycladon that survived the Last Glacial Maximum benefited from the transfer of genetic information through hybridization. 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.

Taxonomy, ecology, and conservation of Sporadanthus (Restionaceae) in New Zealand

Abstract A new species, Sporadanthus ferru‐gineus (Restionaceae), is described from the peat bogs of the northern North Island, New Zealand. It is distinguished from S. traversii by its more robust, brittle culms with swollen bases, different coloured rhizome scales and culms, and smaller, dehiscent fruit. In the past S. ferrugineus has been referred to Sporadanthus traversii, which is now treated as a Chatham Island endemic. Because of this past confusion a detailed description for S. traversii is also provided and a lectotype for the species selected. The ecology of both species of Sporadanthus is reviewed. There are marked differences in their preferred habitats and response to fire. In particular, Sporadanthus ferrugineus is a late‐successional species of raised peat bogs. Within these ecosystems, S. ferrugineus is eliminated by fire and re‐establishment is from seed subsequently deposited by remnant plants. Following fire, S. ferrugineus takes five years to recolonise former habitat and requires 12 y...