Steven J. Wagstaff

Plant dispersal N.E.W.S from New Zealand.

Although New Zealand separated from Gondwana during the late Cretaceous (80 million years ago) it shares strong floristic affinities with other Southern Hemisphere landmasses. For 150 years, biogeographers have debated whether these similarities reflect the ancient Gondwanan connection or subsequent dispersal events. Molecular phylogenies are providing new insights into the history of Southern Hemisphere plant groups. These studies show that many plant lineages are recent arrivals in New Zealand, diversifying rapidly and then travelling to other Southern Hemisphere landmasses.

Evolution and biogeography of the Hebe complex (Scrophulariaceae) inferred from ITS sequences

Abstract The Hebe complex comprises a putatively monophyletic group distributed from eastern Australia and New Guinea to the Falkland Islands. Analysis of ITS sequences supports five distinct clades within the complex, corresponding to Derwentia plus Hebe formosa, Heliohebe, Chionohebe plus Parahebe trifida, Parahebe, and Hebe. Hebe cheesemanii and Hebe cupressoides form a weakly supported Glade that is distinct from the Hebe Glade. Relationships of Hebe macrantha are poorly resolved. The currently recognised infra‐generic classification of Hebe is not supported by this study, and the newly described genus Leonohebe Heads is considered polyphyletic. These results suggest that the progenitor of the Hebe complex originated in Australia. A rapid and extensive radiation followed establishment of a founder population in New Zealand. The combined effects of inbreeding, genetic drift, and strong selection on small populations fragmented by mountain‐building and glacia‐tion have contributed to its rapid evolution...

Phylogenies reveal predictive power of traditional medicine in bioprospecting

There is controversy about whether traditional medicine can guide drug discovery, and investment in bioprospecting informed by ethnobotanical data has fluctuated. One view is that traditionally used medicinal plants are not necessarily efficacious and there are no robust methods for distinguishing those which are most likely to be bioactive when selecting species for further testing. Here, we reconstruct a genus-level molecular phylogenetic tree representing the 20,000 species found in the floras of three disparate biodiversity hotspots: Nepal, New Zealand, and the Cape of South Africa. Borrowing phylogenetic methods from community ecology, we reveal significant clustering of the 1,500 traditionally used species, and provide a direct measure of the relatedness of the three medicinal floras. We demonstrate shared phylogenetic patterns across the floras: related plants from these regions are used to treat medical conditions in the same therapeutic areas. This finding strongly indicates independent discovery of plant efficacy, an interpretation corroborated by the presence of a significantly greater proportion of known bioactive species in these plant groups than in random samples. We conclude that phylogenetic cross-cultural comparisons can focus screening efforts on a subset of traditionally used plants that are richer in bioactive compounds, and could revitalize the use of traditional knowledge in bioprospecting.

Classification, Origin, and Diversification of the New Zealand Hebes (Scrophulariaceae)

The New Zealand hebes (Scrophulariaceae) are members of a large Southern Hemisphere clade nested within Veronica. Analysis of ITS and rbcL sequences suggests that the New Zealand species are derived from a single common ancestor that arrived via long-distance dispersal. After the establishment of this initial founder population in New Zealand, the hebes have undergone at least two major episodes of diversification, giving rise to six clades. The great degree of morphological diversity in the New Zealand hebes contrasts with a corresponding low level of sequence divergence. New Zealand was a source of new emigrants to other regions in the South Pacific that were preadapted to high mountains or forest margins. Our results suggest that two instances of long-distance dispersal from New Zealand to South America, at least one instance from New Zealand to Australia, and one instance from New Zealand to New Guinea have occurred relatively recently. Shorter hops to the Chatham Islands and the subantarctic islands are also supported by the sequence data.

Phylogeny of Labiatae and Verbenaceae Inferred from rbcL Sequences

Parsimony analysis of rbcL sequences supports monophyly of the Labiatae s.l., which includes the Labiatae, subfamilies Caryopteridoideae, Chloanthoideae, and Viticoideae of the Verbenaceae, and Symphoremataceae. Representatives of subfamily Verbenoideae (Verbenaceae s. str.) do not form a monophy- letic group with the Labiatae s.l. Avicennia (Avicenniaceae), Cyclocheilon (Nesogenaceae), and Euthystachys and Retzia (Stilbaceae), included in the Verbenaceae by many authors, are distinct from the Labiatae s.l. and Verbenaceae s. str. The inferred phylogeny also provides a framework to interpret character evolution. Results suggest that uniovulate locules have evolved in at least two lineages of Lamiales s.l. and that a gynoecium with four locules by the development of false partitions apparently has evolved independently in the Labiatae s.l. and th,e Verbenaceae s. str. Whereas a dry fruit is plesiomorphic in the Lamiales s.l., a fleshy fruit is plesiomorphic in the Labiatae s.l. with possible reversal in four lineages.

Convergent evolution of shoots in land plants: lack of auxin polar transport in moss shoots.

SUMMARY The shoot is a repeated structure made up of stems and leaves and is the basic body plan in land plants. Vascular plants form a shoot in the diploid generation, whereas nonvascular plants such as mosses form a shoot in the haploid generation. It is not clear whether all land plants use similar molecular mechanisms in shoot development or how the genetic networks for shoot development evolved. The control of auxin distribution, especially by polar auxin transport, is essential for shoot development in flowering plants. We did not detect polar auxin transport in the gametophytic shoots of several mosses, but did detect it in the sporophytes of mosses without shoot structure. Treatment with auxin transport inhibitors resulted in abnormal embryo development, as in flowering plants, but did not cause any morphological changes in the haploid shoots. We fused the soybean auxin‐inducible promoter GH3 with a GUS reporter gene and used it to indirectly detect auxin distribution in the moss Physcomitrella patens. An auxin transport inhibitor NPA did not cause any changes in the putative distribution of auxin in the haploid shoot. These results indicate that polar auxin transport is not involved in haploid shoot development in mosses and that shoots in vascular plants and mosses are most likely regulated differently during development.

The Evolution of Araliaceae: A Phylogenetic Analysis Based on ITS Sequences of Nuclear Ribosomal DNA

Abstract Phylogenetic analyses of ITS sequence data from 70 species and 40 genera of Araliaceae (representing all major lineages within the “core group” of the family) do not support the widely used traditional division of Araliaceae into three tribes. Tribe Aralieae (characterized by imbricate petals) is found nested within a paraphyletic Schefflerieae (whose taxa have valvate petals). There are, however, two large monophyletic groups comprising most araliad genera: the ”Aralia-Polyscias-Pseudopanax group” (which includes Aralia, Meryta, Munroidendron, Panax, Pentapanax, Polyscias, Pseudopanax, Reynoldsia, Sciadodendron, Tetraplasandra, and their close allies), and the ”Eleutherococcus-Dendropanax-Schefflera group” (including Brassaiopsis, Dendropanax, Eleutherococcus, Fatsia, Hedera, Oreopanax, Schefflera, Sinopanax, and their close allies). The ITS trees also permit a re-evaluation of several taxonomically important morphological characters (e.g., petal aestivation, leaf architecture, carpel number, and habit), and provide the opportunity to assess traditional generic delimitations in the family. Four of the largest genera appear to be either polyphyletic (Schefflera, Pseudopanax) or paraphyletic (Aralia, Polyscias), but further studies will be needed to fully re-define these complex taxa. Outgroup comparisons and the placement of Astrotricha and Osmoxylon (in basally-branching lineages in Araliaceae) help to confirm a paleotropical origin of the family. The ITS topologies suggest that biogeographic radiations into different tropical/subtropical regions and into the north and south temperate regions occurred early in the history of core Araliaceae. Temperate taxa have arisen several times independently from tropical and subtropical relatives, although a few subtropical taxa may be found nested within temperate clades (e.g., Pentapanax within Aralia). Migrations between the Old and New Worlds are also suggested for several taxa, including Aralia, Panax, Oplopanax, and the Sinopanax—Oreopanax generic pair. Communicating Editor: Alan Whittemore

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.

High-resolution coproecology: using coprolites to reconstruct the habits and habitats of New Zealand's extinct upland moa (Megalapteryx didinus).

Knowledge about the diet and ecology of extinct herbivores has important implications for understanding the evolution of plant defence structures, establishing the influences of herbivory on past plant community structure and composition, and identifying pollination and seed dispersal syndromes. The flightless ratite moa (Aves: Dinornithiformes) were New Zealand’s largest herbivores prior to their extinction soon after initial human settlement. Here we contribute to the knowledge of moa diet and ecology by reporting the results of a multidisciplinary study of 35 coprolites from a subalpine cave (Euphrates Cave) on the South Island of New Zealand. Ancient DNA analysis and radiocarbon dating revealed the coprolites were deposited by the extinct upland moa (Megalapteryx didinus), and span from at least 6,368±31 until 694±30 14C years BP; the approximate time of their extinction. Using pollen, plant macrofossil, and ancient DNA analyses, we identified at least 67 plant taxa from the coprolites, including the first evidence that moa fed on the nectar-rich flowers of New Zealand flax (Phormium) and tree fuchsia (Fuchsia excorticata). The plant assemblage from the coprolites reflects a highly-generalist feeding ecology for upland moa, including browsing and grazing across the full range of locally available habitats (spanning southern beech (Nothofagus) forest to tussock (Chionochloa) grassland). Intact seeds in the coprolites indicate that upland moa may have been important dispersal agents for several plant taxa. Plant taxa with putative anti-browse adaptations were also identified in the coprolites. Clusters of coprolites (based on pollen assemblages, moa haplotypes, and radiocarbon dates), probably reflect specimens deposited at the same time by individual birds, and reveal the necessity of suitably large sample sizes in coprolite studies to overcome potential biases in diet interpretation.

Phylogenetic relationships within the tribe Malveae (Malvaceae, subfamily Malvoideae) as inferred from ITS sequence data

Phylogenetic relationships among genera of tribe Malveae (Malvaceae, subfamily Malvoideae) were reconstructed using sequences of the internal transcribed spacer (ITS) region of the 18S-26S nuclear ribosomal repeat. Newly generated sequences were combined with those available from previous generic level studies to assess the current circumscription of the tribe, monophyly of some of the larger genera, and character evolution within the tribe. The ITS data do not support monophyly of most generic alliances as presently defined, nor do the data support monophyly of several Malveae genera. Two main well-supported clades were recovered, which correspond primarily to taxa that either possess or lack involucral bracts, respectively. Chromosomal evolution has been dynamic in the tribe with haploid numbers varying from n = 5 to 36. Aneuploid reduction, hybridization, and/or polyploidization have been important evolutionary processes in this group.