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Vernonia (Asteraceae: Vernonieae) is monophyletic if circumscribed to include only a North American clade of ca. 20 species. Vernonia pratensis, an endemic species of Madagascar, has been placed in the synonymy of Cyanthillium patulum or considered a distinct species in Bothriocline. In this study we characterise the pollen and cypsela of Vernonia pratensis, Bothriocline longipes, and Cyanthillium patulum with details on morphology and ultra-sculpture. The pollen grains of these species are 3-brevicolporate or 3-porate and echinolophate; in B. longipes and V. pratensis there is an inconspicuous colpus formed by interlacunar gaps (absent in C. patulum). The cypselae of B. longipes and V. pratensis have prominent ribs, broader or equally as wide as the grooves and that are fused into a shallow, apical rim; the grooves are covered by unicellular trichomes (type 1) with a striate cuticle. By contrast, the cypselae of C. patulum have ribs narrower than the grooves and not fused apically; the grooves are covered by infundibular idioblasts, and bilobed glandular trichomes at the base. Based on these morphological findings, V. pratensis is here placed in Bothriocline and named B. madagascariensis. This is the single species that occurs in Madagascar within a genus of ca. 50 species otherwise restricted to Tropical Africa and subtropical Southern Africa. Full palynological descriptions, measurements, and scanning electron microscopy (SEM) and light microscopy (LM) images are provided for the three species (B. longipes, B. madagascariensis, and C. patulum), as well as a full taxonomic description of B. madagascariensis, with a preliminary conservation status assessment, nomenclatural notes, and a discussion of possible relationships with other species of Bothriocline. 

Centauropsis is a genus of eight species in the family Compositae, all of which are endemic to Madagascar. There is almost no information about the pollen of this genus, with only one species having its pollen described to date, which hinders systematic studies involving this genus and closely related taxa. In this study, we comprehensively characterise the pollen of Centauropsis, with details on morphology and ultrasculpture for six of the eight species of the genus. The pollen of Centauropsis is here characterised as 3-colporate, with sublophate ornamentation and nanoreticulate sexine. The species differ from each other mostly in length of the axis, morphology of the colporus endoaperture, and spine shape and size. The correlation between palynological characters and their variation within and between species was explored using principal component analyses (PCA) and cluster analyses (unweighted pair group method with arithmetic mean [UPGMA] and Euclidean distance). Full palynological descriptions, measurements and scanning electron microscopy (SEM) and light microscopy (LM) images are provided for all examined species. 

Abstract Distephanus Cass. comprises 43 distinctive species of shrubs and small trees that have been placed historically within the ironweed tribe, Vernonieae (Asteraceae). Using the most expansive sampling of Distephanus to date, this study aims to test the monophyly of this genus and facilitate its classification. Molecular phylogenetic analyses were conducted using four molecular markers from the nuclear and plastid genomes. These data also supported divergence dating analyses that were performed to understand the timing of diversification events within Distephanus and other related genera as well as ancestral area reconstruction analyses to infer the biogegraphic history of species diversity in this group. Results from this study indicate that, as currently circumscribed, Vernonieae is not monophyletic and that Distephanus is, in fact, sister to a clade that comprises Vernonieae and another tribe, Moquinieae, which only includes two species restricted to Brazil. On the basis of these findings, Distephanus is classified in a new tribe that we describe here, Distephaneae. This new tribe comprises 41 species of Distephanus that are easily distinguished from Moquinieae and Vernonieae based on the presence of florets with yellow corollas and trinervate leaves. 

Summary Poales are one of the most species‐rich, ecologically and economically important orders of plants and often characterise open habitats, enabled by unique suites of traits. We test six hypotheses regarding the evolution and assembly of Poales in open and closed habitats throughout the world, and examine whether diversification patterns demonstrate parallel evolution.We sampled 42% of Poales species and obtained taxonomic and biogeographic data from the World Checklist of Vascular Plants database, which was combined with open/closed habitat data scored by taxonomic experts. A dated supertree of Poales was constructed. We integrated spatial phylogenetics with regionalisation analyses, historical biogeography and ancestral state estimations.Diversification in Poales and assembly of open and closed habitats result from dynamic evolutionary processes that vary across lineages, time and space, most prominently in tropical and southern latitudes. Our results reveal parallel and recurrent patterns of habitat and trait transitions in the species‐rich families Poaceae and Cyperaceae. Smaller families display unique and often divergent evolutionary trajectories.The Poales have achieved global dominance via parallel evolution in open habitats, with notable, spatially and phylogenetically restricted divergences into strictly closed habitats. 

Abstract Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods^1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome^3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins^5–7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes⁸. This 15-fold increase in genus-level sampling relative to comparable nuclear studies⁹provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.