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 studies⁹ provides 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.

Open habitats such as grasslands occupy < 5% of the Amazon and are currently grouped under the broad term Amazonian savanna, covering an area of c. 267 000 km2, mostly in Brazil and Bolivia. These habitats are found isolated within an extensive rainforest matrix, having a distinct flora from the latter. The lower Amazon River is home to several patches of savanna that occupy both south and north banks of the river, in Santarém, Alenquer and Monte Alegre. Although having an abundance of herbaceous plants, most studies on these open areas focus only on tree species, ignoring the relevant non-woody component of the vegetation. Our objectives were to provide new surveys of seed plants for two Amazonian savanna sites and to take the opportunity to revisit the biogeographical links between Amazonian savanna, Amazonian canga vegetation and the central Brazilian cerrado (CBC) and caatinga, analysing woody and herbaceous plants. We created a floristic database that includes sites of Amazonian savannas, including campinarana, coastal scrub (restinga), CBC and Amazonian campos rupestres (on canga or other substrate). We compared those sites using multivariate analyses to find out the degree of floristic resemblance between sites. We prepared a new list of 406 species of seed plants [336 in Parque Estadual de Monte Alegre (PEMA) and 117 in Serra do Itauajuri (SI)], including 23 new records for the state of Pará and some putative new species for science. The Amazonian savannas form three loosely arranged groups, whereas the Amazonian canga formed a cohesive assemblage. Both groups were contrasted against cerrado and caatinga sites and had a distinctive flora from both. Sites from north-western Pará (Alter do Chão, PEMA and SI) were grouped with their northern counterparts in Roraima. An improved representation of the flora of these sites is provided, with more insight into the relationship between the Amazonian savanna sites and other vegetation types. It is worrying that recent changes of the Brazilian legislation place open environments, such as PEMA, in the path of vulnerability to disturbance and destruction.

This study provides a checklist of angiosperm species from Jalapão region, Tocantins, Brazil, inserted within the Cerrado biome, a global biodiversity hotspot. The region of Jalapão is still well preserved despite current threats to its biodiversity, however its plant diversity is still poorly understood. To generate the present checklist, fieldwork was carried out and relevant herbarium collections were consulted. Angiosperms distributed in the grassland and savanna physiognomies with dry, non-rocky soils were recorded. We detected 550 species within 85 families. The richest families are Leguminosae, Poaceae, Asteraceae, Lamiaceae, Rubiaceae, Myrtaceae, Malpighiaceae and Euphorbiaceae. Among the plant species, ten are listed as rare, ten are threatened, and twelve were identified as new to science. This study increases the number of angiosperm species occurring in these vegetation types in Jalapão almost 2-fold compared to previous inventories. The Cerrado biome and Jalapão region are under heavy threat due to agricultural expansion, and our study contributes to the knowledge of plant biodiversity as a fundamental step towards designing and carrying out conservation actions.

The Atlantic Forest is one of the most diverse and threatened phytogeographical domains in the world. Despite that, it includes regions with poor floristic knowledge, even in protected areas. Although the importance of protected areas in conserving the Atlantic Forest hotspot is undisputed, it is necessary to recognise the floristic richness of these areas to propose effective conservation actions. In this sense, online databases have proved to be a promising tool for compiling species lists with relevant biodiversity information. This study is based on the list of vascular plants of the "Parque Estadual da Pedra Selada", published in the "Catálogo de Plantas das Unidades de Conservação do Brasil". It summarises the species richness, endemism and conservation status of this protected area. The published list of vascular plants was based on data obtained from herbarium collections available in online databases. A total of 303 species have been recorded for the "Parque Estadual da Pedra Selada," of which 297 are native to Brazil, 78 are endemic to the Brazilian Atlantic Forest, and seven are endemic to the State of Rio de Janeiro. More than 60% of the species are woody, and more than 40% are trees. Eight threatened species (Endangered – EN and Vulnerable – VU), of which five are endemic to the State of Rio de Janeiro, are housed in this protected area. One species was classified as Data Deficient (DD). Our results increase the knowledge of the Atlantic Forest flora in the State of Rio de Janeiro and support effective conservation planning for this protected area.