Systematics of Xanthorrhoeaceae Sensu Lato, with an Emphasis on Bulbine

We provide here results of a combined analysis of plastid genes rbcL, matK, and ndhF for Xanthorrhoeaceae s.l., the Asphodelaceae/Xanthorrhoeaceae/Hemerocallidaceae clade, which are well supported by the DNA data. Xanthorrhoea (often treated as the sole member of Xanthorrhoeaceae) is sister to the hemerocallid clade (former Hemerocallidaceae); and the asphodelid clade (formerly Asphodelaceae) is sister to them both. For additional species of Bulbine and Jodrellia (both Asphodeloideae), we also collected rps16 intron and ITS nuclear ribosomal DNA sequences to better assess their relationships. Bulbine, with Jodrellia, embedded are sister to the collective genera of subfamily Alooideae in which all species are characterized by strongly bimodal and nearly identical karyotypes, whereas that of Bulbine is much more variable. Cytological studies have previously shown Bulbine to possess a range of karyotypes from graduated to clearly bimodal (although never exactly like the aloid genera) and point toward a lower level of bimodality in the Australian members, all of which are autotetraploid, than in the African members, all of which are diploid. Therefore, there have been two events of particular interest within Bulbine, a change in ploidy and a long-range dispersal event

Multigene Analyses of Monocot Relationships

We present an analysis of supra-familial relationships of monocots based on a combined matrix of nuclear I8S and partial 26S rDNA, plastid atpB, matK, ndhF, and rbcL, and mitochondrial atp1 DNA sequences. Results are highly congruent with previous analyses and provide higher bootstrap support for nearly all relationships than in previously published analyses. Important changes to the results of previous work are a well-supported position of Petrosaviaceae as sister to all monocots above Acorales and Alismatales and much higher support for the commelinid clade. For the first time, the spine of the monocot tree has some bootstrap support, although support for paraphyly of liliids is still only low to moderate (79-82%). Dioscoreales and Pandanales are sister taxa (moderately supported, 87- 92%), and Asparagales are weakly supported (79%) as sister to the commelinids. Analysis of just the four plastid genes reveals that addition of data from the other two genomes contributes to generally better support for most clades, particularly along the spine. A new collection reveals that previous material of Petermannia was misidentified, and now Petermanniaceae should no longer be considered a synonym of Colchicaceae. Arachnitis (Corsiaceae) falls into Liliales, but its exact position is not well supported. Sciaphila (Triuridaceae) falls with Pandanales. Trithuria (Hydatellaceae) falls in Poales near Eriocaulaceae, Mayacaceae, and Xyridaceae, but until a complete set of genes are produced for this taxon, its placement will remain problematic. Within the commelinid clade, Dasypogonaceae are sister to Poales and Arecales sister to the rest of the commelinids, but these relationships are only weakly supported

Nomenclature and typification in Polyosma (Escalloniaceae) from New Caledonia, with the description of a new species

The taxonomy of Polyosma (Escalloniaceae) in New Caledonia is reviewed. All names validly published in Polyosma in this archipelago are discussed and lectotypified when necessary and possible. A new combination is made, Polyosma subintegrifolia; and a new species, Polyosma kouaouana, is described. Seven species (all endemic) are recognized in New Caledonia: P. brachystachys, P. discolor, P. kouaouana, P. leratii, P. pancheriana, P. spicata, and P. subintegrifolia. A preliminary identification key is provided

The inequity of species names: The flora of New Caledonia as a case study

International audienceSince Linnaeus popularized the system of binomial nomenclature to describe living organisms, it has been common practice to name species after people (eponyms). Trends in species naming were analyzed in the endemic flora of New Caledonia, a biodiversity hotspot in the South-West Pacific. It was found that eponyms were predominantly from France and other European countries, and to a lesser extent from neighboring countries in Oceania or North America. Today, just 7% of these eponyms were born in New Caledonia, and 6% were women. Most of the corresponding species were described in the past five decades. Although the evidence is still preliminary, the name of a species appears to have a significant impact on how people relate to it, and this may be especially important for threatened endemic species and the willingness of local populations to preserve them. Because newly described species are often rare and endangered, adopting a more balanced approach to species naming may help to secure their future, particularly given the current extinction crisis

Focus on Geissois (Cunoniaceae): another example of the melanesian connection

International audienceThe genus Geissois, taken in the strict sense (i.e., excluding the Australian species), a member of the family Cunoniaceae, is a group of trees and shrub

Biodiversité, origine et évolution des Cunoniaceae : implications pour la conservation de la flore de Nouvelle-Calédonie

New Caledonia is considered as a biodiversity hotspot because of its rich, unique and threatened flora. In order to better understand the history of this flora, a study was carried out on the Cunoniaceae family, which comprises 88 species and 7 genera of shrubs and trees in New Caledonia, including “faux-tamanou” and “chêne rouge”. Four new species in the genus Codia and two in the genus Cunonia have been described. A molecular phylogeny of the genera Acsmithia and Spiraeanthemum suggest that they should be considered as a single genus: Spiraeanthemum, because of the paraphyly of Acsmithia. The Cunoniaceae of New Caledonia have greatest biogeographical affinities with Australian ones, as for the entire flora of the archipelago. Nevertheless, a global comparative analysis including all flowering plants shows that some lineages are over- or under-repressented in New Caledonia, and this can not entirely be explained by biogeography. It seems possible that some lineages possess an exaptation (“pre-adaptation”) to grow on ultramafic soils (serpentine in a broad sense), that could have facilitated their settlement and diversification on the archipelago. This is for example the case of the COM clade (Celastrales, Oxalidales and Malpighiales) to which Cunoniaceae belong. The evolutionary history of the genus Codia was reconstructed using molecular markers and indicates that adaptation to ultramafic soils may be ancestral to the entire genus. Hybridisation has played an important role in the diversification of the genus, and several species of hybrid origin have morphological characters that are not found in parental species (transgressive phenotypes). Some parental species that used to hybridise no longer co-occur, suggesting that considerable range alteration has happened, and this may be linked to the Quaternary ice ages. In the genus Spiraeanthemum, considerable genetic differences have been observed within S. ellipticum and S. pubescens between southern populations on ultramafic soils and northern population on non- ultramafic soils, suggesting the existence of cryptic species. The archipelago also hosts several relict lineages which represent an important phylogenetic diversity. In Cunoniaceae, a significant correlation was found between systematics and bioactivity. Phylogenetic diversity is therefore positively correlated with the potential value of biodiversity, justifying its conservation. Considering the threats to the New Caledonian flora, including fire, invasive species, mining and climate change, it is important to implement the best strategy for its preservation. Thus it will be necessary to protect the relict lineages and also to preserve the processes that generate new species. This includes protecting the sites with a mosaic of soils where species with different ecology come into contact and can hybridize.La Nouvelle-Calédonie est considérée comme une zone prioritaire pour la préservation de la biodiversité à l'échelle mondiale en raison de sa flore riche, originale et menacée. Pour mieux comprendre l'histoire de cette flore, une étude a été menée sur la famille des Cunoniaceae, qui compte dans l'archipel 88 espèces et 7 genres d'arbres et d'arbustes, dont le « faux-tamanou » et le « chêne rouge ». Quatre nouvelles espèces dans le genre Codia et deux dans le genre Cunonia ont été mises en évidence. Une phylogénie moléculaire des genres Acsmithia et Spiraeanthemum suggère qu'ils devraient être considérés comme un seul genre : Spiraeanthemum, car le genre Acsmithia est paraphylétique. Sur un plan biogéographique, les affinités des Cunoniaceae et de la flore de Nouvelle-Calédonie sont plus fortes avec l'Australie. Néanmoins, une analyse comparative globale à l'échelle de l'ensemble des plantes à fleurs montre que certaines lignées sont surreprésentées en Nouvelle-Calédonie, et d'autres sont sous-représentées, et ceci ne peut pas être entièrement expliqué par la biogéographie. Il semblerait que certaines lignées possèderaient une exaptation (« pré-adaptation ») aux sols ultramafiques (terrains miniers) qui aurait pu faciliter leur installation et leur diversification sur l'archipel. C'est notamment le cas du clade COM (Celastrales, Oxalidales et Malpighiales) auquel appartiennent les Cunoniaceae. L'histoire évolutive du genre Codia a été reconstruite à l'aide de marqueurs moléculaires et indique que l'adaptation aux terrains miniers est potentiellement ancestrale dans ce genre. L'hybridation a joué un rôle important dans la diversification du genre, et plusieurs espèces d'origine hybride présentent des caractères morphologiques absents chez les espèces parentales (phénotypes transgressifs). Certaines espèces qui se sont hybridées ont des distributions clairement distinctes aujourd'hui, suggérant des changements dans la répartition de ces espèces pouvant être liés aux périodes glaciaires du Quaternaire. Chez le genre Spiraeanthemum, des différences génétiques nettes ont été observées au sein de S. ellipticum et S. pubescens entre les populations du sud de la Grande Terre sur sol ultramafique et les populations du nord sur sol non¬ultramafique, suggérant l'existence d'espèces cryptiques. La flore de l'archipel possède également de nombreuses lignées reliques qui représentent une importante diversité phylogénétique. Chez les Cunoniaceae, une corrélation significative a été trouvée entre la position systématique et l'activité biologique des espèces. La diversité phylogénétique serait ainsi corrélée positivement à la valeur potentielle de la biodiversité, ce qui justifierait sa conservation. Face aux menaces qui pèsent sur la flore de la Nouvelle-Calédonie, notamment les feux, les espèces envahissantes, l'exploitation minière et le réchauffement climatique, il est important d'employer la meilleure stratégie pour la préservation de la biodiversité. Ainsi, il semble urgent de protéger les lignées reliques, mais aussi de préserver les processus qui permettent l'apparition de nouvelles espèces. Il s'agit notamment de protéger les sites qui présentent une mosaïque de sols où la cohabitation et l'hybridation d'espèces différant par leurs écologies deviennent possibles

A new species of <em>Metrosideros</em> (Myrtaceae) from Vanuatu and notes on the genus

International audienc

Time and tempo of diversification in the flora of New Caledonia

International audienceNew Caledonia is well known for its rich and unique flora. Many studies have focused on the biogeographical origins of New Caledonian plants but rates of diversification on the island have scarcely been investigated. Here, dated phylogenetic trees from selected published studies were used to evaluate the time and tempo of diversification in New Caledonia. The 12 plant lineages investigated all appear to have colonized the island < 37 Mya, when New Caledonia re-emerged after a period of inundation, and the timing of these arrivals is spread across the second half of the Cenozoic. Diversification rates are not particularly high and are negatively correlated with lineage age. The palms have the fastest diversification rates and also the most recent arrival times. The lineage ages of rainforest plants suggest that this ecosystem has been present for at least 6.9 Myr. The New Caledonian flora is apparently a relatively old community that may have reached a dynamic equilibrium. Colonization by new immigrants has been possible until relatively recently and diversity-dependent processes may still be affecting the diversification rates of the earlier colonizers. Further studies on the diversification of large plant clades with exhaustive sampling should help to clarify this

Taxonomic notes on New Caledonian Malpighiales: Acridocarpus, Crossostylis, Erythroxylum, and Xylosma

International audienceTaxonomic notes are made on the Malpighiales of New Caledonia. The names Acridocarpus austrocaledonicus Baill. (Malpighiaceae), Crossostylis grandiflora Brongn. &amp; Gris, C. multiflora Brongn. &amp; Gris, C. sebertii Pancher ex Brongn. &amp; Gris (Rhizophoraceae), and Erythroxylum novocaledonicum O.E.Schultz (Erythroxylaceae) are lectotypified. Based on published molecular phylogenetic and morphological evidence, Lasiochlamys Pax &amp; K.Hoffm. is better treated as a synonym of Xylosma G.Forst. (Salicaceae), and five new combinations and one new name are provided to implement this change