We present an analysis of supra-familial relationships of monocots based on a combined matrix of nuclear ISS and partial 26S rONA, plastid atpB, matK, ndhF, and rbcL, and mitochondrial atpl 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.

Patterns of polyploid evolution in the taxonomically controversial Dactylorhiza incarnata/maculata groups were inferred genetically by analyzing 399 individuals from 177 localities for (1) four polymorphic plastid regions yielding aggregate haplotypes and (2) nuclear ribosomal ITS allele frequencies. Concordance between patterns observed in distributions of plastid haplotypes and ITS alleles renders ancestral polymorphism an unlikely cause of genetic variation in diploids and allopolyploids. Combining the degree of concerted evolution in ITS alleles (thought to reflect gene conversion) with inferred parentage provides support for a quadripartite classification of western European allopolyploid dactylorchids according to their respective parentage and relative dates of origin. The older allotetraploids that generally exhibit only one parental ITS allele can be divided into those derived via hybridization between the divergent complexes we now call D. incarnata s.l. and D. fuchsii (e.g., D. majalis) and those derived via hybridization between D. incarnata s.l. and D. maculata (e.g., D. elata). Similarly, the younger allotetraploids that maintain evidence of both parental ITS alleles can be divided into those derived from hybridization between D. incarnata s.l. and D. fuchsii, or perhaps in some cases a diploid species resembling D. saccifera (e.g., D. praetermissa, D. purpurella, D. traunsteineri s.l., D. baltica), and those derived from hybridization between the D. incarnata s.l. and D. maculata groups (e.g., D. occidentalis, D. sphagnicola). Older allotetraploids are inferred to have passed through glacially induced migration bottlenecks in southern Eurasia, whereas at least some younger allotetraploids now occupying northern Europe are inferred to have originated post‐glacially and remain sympatric with their parents, a scenario that is largely in agreement with the morphology and ecology of these allotetraploids. ITS conversion is in most cases biased toward the maternal parent, eventually obscuring evidence of the original allopolyploidization event because plastid haplotypes also reflect the maternal contribution. Gene flow appears unexpectedly low among allotetraploids relative to diploids, whereas several mechanisms may assist the gene flow observed across ploidy levels. There is good concordance between (1) the genetically delimited species that are required to accurately represent the inferred evolutionary events and processes and (2) morphologically based species recognized in certain moderately conservative morphological classifications previously proposed for the genus. Further research will seek to improve sampling, especially in eastern Eurasia, and to develop more sensitive markers for distinguishing different lineages within (1) the remarkably genetically uniform D. incarnata group (diploids) and (2) locally differentiated populations of (in some cases unnamed) allotetraploids.

Orchids are the largest family of flowering plants, encompassing several times as many species as birds or mammals. Because of their diversity, charisma, and threats from overcollection and habitat loss, they are a key group in conservation. Nevertheless, preservation of this group is plagued by taxonomic problems, particularly in Europe, where new taxa are actively being described. We used a checklist of orchids to compare the taxonomic treatment of this family between Europe and neighboring areas to search for geographical patterns. Numbers of invalid, infraspecific, and hybrid names are significantly higher in Europe than in surrounding areas. Recognition of numerous and poorly circumscribed orchid taxa is a serious obstacle to their conservation because rare, poorly defined species may be prioritized for conservation over taxonomically "good" species. This phenomenon may be the result of the popularity of orchids in Europe. We believe that more taxonomic effort should be made in other areas of the world (e.g., the tropics) and on less charismatic groups.

While an excess of metals such as zinc, cadmium or nickel (Ni) is toxic for most plants, about 500 plant species called hyperaccumulators are able to accumulate high amounts of these metals. These plants and the underlying mechanisms are receiving an increasing interest because of their potential use in sustainable biotechnologies such as biofortification, phytoremediation, and phytomining. Among hyperaccumulators, about 400 species scattered in 40 families accumulate Ni. Despite this wide diversity, our current knowledge of the mechanisms involved in Ni accumulation is still limited and mostly restricted to temperate herbaceous Brassicaceae. New Caledonia is an archipelago of the tropical southwest pacific with a third of its surface (5500 km2) covered by Ni-rich soils originating from ultramafic rocks. The rich New Caledonia flora contains 2145 species adapted to these soils, among which 65 are Ni hyperaccumulators, including lianas, shrubs or trees, mostly belonging to the orders Celastrales, Oxalidales, Malpighiales, and Gentianales. We present here our current knowledge on Ni hyperaccumulators from New Caledonia and the latest molecular studies developed to better understand the mechanisms of Ni accumulation in these plants.