The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold‐temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing on the biogeography of particular groups during the last few decades, a global analysis of Carex biogeography and diversification is still lacking. For this purpose, we built the hitherto most comprehensive Carex‐dated phylogeny based on three markers (ETS–ITS–matK), using a previous phylogenomic Hyb‐Seq framework, and a sampling of two‐thirds of its species and all recognized sections. Ancestral area reconstruction, biogeographic stochastic mapping, and diversification rate analyses were conducted to elucidate macroevolutionary biogeographic and diversification patterns. Our results reveal that Carex originated in the late Eocene in E Asia, where it probably remained until the synchronous diversification of its main subgeneric lineages during the late Oligocene. E Asia is supported as the cradle of Carex diversification, as well as a “museum” of extant species diversity. Subsequent “out‐of‐Asia” colonization patterns feature multiple asymmetric dispersals clustered toward present times among the Northern Hemisphere regions, with major regions acting both as source and sink (especially Asia and North America), as well as several independent colonization events of the Southern Hemisphere. We detected 13 notable diversification rate shifts during the last 10 My, including remarkable radiations in North America and New Zealand, which occurred concurrently with the late Neogene global cooling, which suggests that diversification involved the colonization of new areas and expansion into novel areas of niche space.

Phylogenetic studies of Carex L. (Cyperaceae) have consistently demonstrated that most subgenera and sections are para-or polyphyletic. Yet, taxonomists continue to use subgenera and sections in Carex classification. Why? The Global Carex Group (GCG) here takes the position that the historical and continued use of subgenera and sections serves to (i) organize our understanding of lineages in Carex, (ii) create an identification mechanism to break the~2000 species of Carex into manageable groups and stimulate its study, and (iii) provide a

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

New Zealand is diverse in alpine and subalpine environments, a consequence of Late Tertiary tectonic and climatic change. However, few studies have sought to evaluate the importance of these environments as abiotic drivers in the diversification of plant species. Of particular interest is the Late Tertiary radiation of Pachycladon, an endemic New Zealand genus of alpine cress. Here we report observations on genome-wide levels of differential expression measured in the habitats of two closely related species of Pachycladon with distinct altitudinal preferences. Using Arabidopsis microarrays, we have identified 310 predominantly hormone- and stress-response genes up-regulated in Pachycladon fastigiata and 324 genes up-regulated in Pachycladon enysii. Expression patterns for glucosinolate biosynthesis and hydrolysis genes (MAM1, MAM-I, MAM-D, AOP2, ESP, ESM1) as well as flavonoid biosynthesis genes (F3'H, FLS, FAH1) were found to be species specific. Predicted differences in flavonoid contents were partly confirmed by high performance liquid chromatography analysis. Differences in glucosinolate profiles and glucosinolate hydrolysis products obtained by high performance liquid chromatography and gas chromatography-mass spectrometry analysis, respectively, also supported inferences from expression analyses. Five glucosinolate chemotypes were matched to known Arabidopsis ecotypes, and the potential adaptive significance of these chemotypes has been discussed. Our findings, in contrast to expectations for evolution of the New Zealand flora, suggest that biotic drivers, such as plant-herbivore interactions, are likely to be as important as abiotic drivers in the diversification of Pachycladon.

Craspedia (Asteraceae: Gnaphalieae) is a genus of 23 species found only in Australia and New Zealand. Maximum parsimony and maximum likelihood analyses of ITS and ETS intergenic spacers from the nuclear genome recovered three main lineages. The first lineage consists solely of the Australian species C. haplorrhiza, the relationships of which are unresolved, and the second includes species that are also exclusively Australian in distribution. The third lineage comprises two monophyletic groups; one including all the remaining Australian species sampled and the other, all New Zealand entities sampled. Monophyly of New Zealand Craspedia is also supported by analysis of psbA‐trnH intergenic spacer sequences. Australian alpine species are independently derived from within the two larger Australian lineages. Both major Australian lineages are present in Tasmania suggesting multiple colonisations from mainland Australia. The single lineage of New Zealand Craspedia and the low divergences between Australian and New Zealand Craspedia samples are consistent with the derivation of New Zealand Craspedia via a single dispersal event from south‐east Australia in the Late Tertiary or Quaternary. Compared with Australian Craspedia, the New Zealand species show extensive morphological divergence but little sequence divergence, suggesting a recent and rapid species radiation.

Carex (Cyperaceae), with an estimated 2000 species, nearly cosmopolitan distribution and broad range of habitats, is one of the largest angiosperm genera and the largest in the temperate zone. In this article, we provide argument and evidence for a broader circumscription of Carex to add all species currently classified in Cymophyllus (monotypic), Kobresia (c. 60 species), Schoenoxiphium (c. 15 species) and Uncinia (c. 70 species) to those currently classified as Carex. Carex and these genera comprise tribe Cariceae (subfamily Cyperoideae, Cyperaceae) and form a well‐supported monophyletic group in all molecular phylogenetic studies to date. Carex as defined here in the broad sense currently comprises at least four clades. Three are strongly supported (Siderostictae, core Vignea and core Carex), whereas the caricoid clade, which includes all the segregate genera, receives only weak to moderate support. The caricoid clade is most commonly split into two clades, one including a monophyletic Schoenoxiphium and two small clades of species of Carex s.s., and the other comprising Kobresia, Uncinia and mostly unispicate species of Carex s.s. Morphological variation is high in all but the Vignea clade, making it extremely difficult to define consistent synapomorphies for most clades. However, Carex s.l. as newly circumscribed here is clearly differentiated from the sister groups in tribe Scirpeae by the transition from bisexual flowers with a bristle perianth in the sister group to unisexual flowers without a perianth in Carex. The naked female flowers of Carex s.l. are at least partially enclosed in a flask‐shaped prophyll, termed a perigynium. Carex s.s. is not only by far the largest genus in the group, but also the earliest published name. As a result, only 72 new combinations and 58 replacement names are required to treat all of tribe Cariceae as a single genus Carex. We present the required transfers here, with synonymy, and we argue that this broader monophyletic circumscription of Carex reflects the close evolutionary relationships in the group and serves the goal of nomenclatural stability better than other possible treatments. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179, 1–42.

While examining herbarium specimens of Trithuria inconspicua Cheeseman, we observed differences in the stigmatic hairs among plants from New Zealand’s North and South Islands. This motivated us to assess genetic and morphological variation within this species and its sister T. filamentosa Rodway from Tasmania. Samples were collected from lakes in the three disjunct geographic areas where the two species occur. Genetic variation in both species was assessed with simple sequence-repeat (SSR, microsatellite) markers and analyses of genetic distances. We also compared the morphology of northern and southern New Zealand T. inconspicua using fresh material. Samples of each species clustered together in a minimum evolution tree built from genetic distances. Trithuria filamentosa had more genetic diversity than did T. inconspicua. Within T. inconspicua, plants from lakes in the North Island and the South Island formed discrete genetic groups diagnosable by subtle morphological differences. Low levels of heterozygosity in both species are consistent with a high level of selfing, as suggested for other co-sexual Trithuria species, but unusual for a putative apomict. On the basis of genetic and morphological variation, we propose recognition of the northern New Zealand and southern New Zealand lineages of T. inconspicua at subspecies rank.

Three morphologically distinct forms of Craspedia grow together in a small area of Mt Arthur (New Zealand) where they appear to remain distinct. Amplified fragment length polymorphism (AFLP) was investigated at the site. Although sample sizes were small, the results indicate that these three distinct forms are reproductively isolated from each other. Further, the level of polymorphism within each suggests that they are not composed of clones or highly selfing lineages. Amplified fragment length polymorphism provides a powerful tool for examining gene flow and reproductive isolation in sympatric Craspedia populations. These results also suggest that it may be possible to recognize reproductively isolated forms as species within the New Zealand radiation of Craspedia. However, taxonomic changes are considered premature at this time.