ABSTRACT In this study, pollen grains of Harleyodendron unifoliolatum, Holocalyx balansae, and Uribea tamarindoides, three monospecific genera with Neotropical distribution belonging to the clade Exostyleae, one of the basal lineages of the family Leguminosae, subfamily Papilionoideae, were analyzed. The palynological material was acetolyzed and analyzed under light microscopy (LM) and scanning electron microscopy (SEM). Under LM, small and medium-sized pollen grains were observed, which showed a prolate-spheroidal to prolate shape, 3-colporate, microreticulate and reticulate exine, sexine and nexine of equal thickness in Harleyodendron and Holocalyx, while the sexine was thicker than nexine in Uribea. Analysis under SEM showed finely granulate, psilate, and granulate apertural membrane, while the exine ornamentation varied from perforate-microechinate in Harleyodendron, to perforate in Holocalyx, while in Uribea showed an irregular relief and granular projections on the perforate tectum. The pollen morphology of these species is similar to each other, varying in sexine/nexine ratio, apertural membrane, and exine ornamentation. Harleyodendron has a finely granulate apertural membrane, sexine and nexine of equal thickness, and a perforate-microreticulate exine ornamentation, Holocalyx shows a psilated apertural membrane, sexine and nexine of equal thickness, and exine ornamentation perforate, and Uribea has a granulate apertural membrane, sexine thicker than nexine, and exine ornamentation with granular projections.

ABSTRACT Climate change is expected to increase the occurrence of severe droughts in the tropics, and little is known about its influence on tree dynamics. Tree-ring width and remote sensing tools can help understand the impacts of climate change on tree growth. We evaluated the applicability of NDVI to obtain phenological metrics (e.g., start, peak, end, and length of growth season) and explored its relationship with tree-ring width of Tectona grandis (teak). The phenological metrics and tree-ring width were correlated with each other, and with both local (temperature, precipitation, solar insolation, Standardized Precipitation Evapotranspiration Index - SPEI) and large-scale (El Niño) climatic variables. The length of season and tree-ring width of teak were positively correlated with precipitation and negatively correlated with temperature in the initial months of the growth period. Tree-ring width was negatively correlated with El Niño events. Climate variables and length of season from the prior period were correlated with the tree-ring width of the current growing period. This study demonstrated that rather than directly affecting productivity, climate might also affect the length of the growing season, which would affect tree growth in the next season.

ABSTRACT As part of floristic surveys in the Southern Cone of South America and the Flora do Brasil 2020 project, we present a revision of Osmundaceae in Brazil. Osmundaceae is represented by two genera (Osmundastrum and Osmunda) and three species. One of them, Osmunda piresii, is endemic to the savannas of Central Brazil, occurring in the states of Goiás, Minas Gerais, and Mato Grosso. Osmunda gracilis is synonymized under Osmunda spectabilis. We present a dichotomous key, descriptions, diagnostic illustrations, distributions, and notes on taxonomy and ecology.

ABSTRACT During fieldwork in the Campos Amazônicos National Park, Amazonas state, Brazil, a new endemic species of Mabea was collected in savanna areas. Field collections and specimens in RON, MG, and HRCB were analyzed. To understand the species distribution and verify possible areas of occurrence, niche modeling was conducted using the sdm package in R. Mabea dalyana, the new species is a subshrub with xylopodia and reduced size (less than 1 m height) and small, yellow thyrses. There are several allopatric species of Mabea growing in Amazonian savannas, some widespread but others locally restricted, such as M. uleana from central Amazonia that has some superficial resemblance in leaves and inflorescences but can be distinguished from M. dalyana by pubescent adaxial leaf surface (vs. glabrous), 12-21 submarginal glands (vs. 10 submarginal glands), thyrse brownish to red (vs. yellow thyrse) and conspicuous caruncle (vs. caruncle inconspicuous). M. dalyana is endemic to hyperseasonal savanna, very well adapted to savanna, and fire tolerant. It has notable characteristics, such as a subshrub habit, a xylopodium, glabrous leaves, and sepals noticeably larger than the ovary.

ABSTRACT An updated checklist of the Orchidaceae from the state of Maranhão is provided. We confirmed 51 genera and 119 species, of which the most representative genera are Habenaria (17 spp.), Catasetum (14 spp.) and Epidendrum (10 spp.). Our checklist includes 30 species that are not listed in the Flora do Brasil for the state, many of which, however, have been recorded in previous publications. Thus, excluding these, six species are cited here for the first time to Maranhão, all of which are also new records for the Brazilian Northeast region. Comparing such data with previous lists, with 103 and 105 species, we detected a strong incongruity among the data. Of the former list, 25 species lack vouchers from the state and were not collected in our expeditions, thus these taxa are not confirmed, while of the latter we found 20 species that are also not confirmed for the same reasons. A list with the 34 excluded taxa is provided. Most of the collection effort in the state coincides with university campuses, and the northwestern region is the most species rich, but unfortunately it is also the most threatened area.

ABSTRACT A new combination and a new status, Pachira manausensis, is here proposed. After making field observations and analyzing type and herbarium specimens, we realized that P. aquatica var. manausensis should be treated as a species due to many morphological and distribution differences compared to the typical variety. We provide detailed descriptions and a distribution map, table, key, and plate to distinguish both species using morphological characteristics. Typifications and nomenclatural notes for related names were performed.

ABSTRACT Studies involving endophytic fungi isolated from endemic plants and their antibacterial potential are largely unknown in the Pampa biome. In this study, we identified endophytic fungi isolated from Kelissa brasiliensis (Iridaceae), an endemic species of the Brazilian Pampa, and assessed their antibacterial activity. Endophytic fungi were first grouped based on macro-and micro-morphology, and one representative of each morphospecies was analyzed using sequences from the internal transcribed spacer (ITS) rDNA region. We then tested the fungal extracts against laboratory isolates of Staphylococcus aureus and Escherichia coli for antibacterial activity. A total of 30 endophytes were isolated from the tissues of K. brasiliensis, with the majority from the leaves. Endophytes were then grouped into seven morphospecies based on their morphological features and one representative from each was selected for phylogenetic analysis. The inference from the ITS rDNA sequences identified the endophytes of the seven selected morphospecies as belonging to six taxonomic groups: Colletotrichum (two), Diaporthe (one), Epicoccum (one), Fusarium (one), and Pestalotiopsis (one). The endophyte extracts revealed better results against E. coli than S. aureus, although the extracts from Colletotrichum and Pestalotiopsis sp. were statistically similar to the control antibiotic. Our study is a basis for endophytic fungi studies in Pampa.

ABSTRACT Croton section Adenophylli is the largest section in the genus, with around 223 species distributed in the neotropical region. One of the main diagnostic characteristics of this section is the fruit columella, which has three prominent ascending terminal appendages. During a taxonomic review of this section in Brazil, we observed that C. campestris has a problematic taxonomic circumscription, thereby being confused with some other congeners. We investigate the circumscription of C. campestris through the examination of several herbarium specimens across its entire geographic range, and in its different habitats. We conducted macro- and micro-morphological studies as well as molecular analyses based on DNA sequences. Our results allow us to propose two new species (C. hatschbachii and C. stellatorotatus), update the nomenclature of C. campestris and C. subvillosus, and define the systematic positions, phylogenetic relationships, morphology and leaf anatomy of the above-mentioned taxa. The species are described, and their geographic distributions, morphological relationships, flowering and fruiting times, and conservation statuses are commented on. The two new species are also illustrated. Seventeen new synonyms, thirteen lectotypes and two neotypes are proposed. We also provide a key for the identification of 11 taxa belonging to the section Adenophylli, previously confused with C. campestris.

ABSTRACT Alpinia is considered the largest genus of Zingiberaceae with ca. 250 species occurring in tropical and subtropical Asia, Australia, and Pacific Islands. The historical biogeography of Alpinia was conducted to explain where Alpinia originated and how it migrated to other regions. The phylogeny, divergence times and ancestral area reconstruction of Alpinia were performed by using the molecular data based on the comprehensive taxon sampling. Our results provide an objective approach to understand the historical biogeography of Alpinia. The genus originated in Asia during the Late Cretaceous ca. 69 Ma and started to diverge after the K-Pg boundary during the early Paleocene with the presence and development of the tropical rainforest and a warm, moist climate. Alpinia migrated to Malesia and then dispersed to Australasia. The molecular analyses supported the diversification of Alpinia in Asia and Malesia. Additionally, the Indian Alpinia has likely a common ancestor with Renealmia and Aframomum, and it is possible that after originating in Asia, Alpinia migrated from Asia to India then to Africa during the early period of collision between the Indian subcontinent and Eurasia to form the common ancestor of Indian Alpinia, Renealmia, and Aframomum. Our phylogeny provides a framework for studies in biogeography, comparative ecology, and evolution.

ABSTRACT Acisanthera saxatilis is described, illustrated, and compared with putative relatives. The first specimen of this new species was collected 119 years ago by Oskar Andersson Gustaf Malme during his "second expedition Regnelliana". Acisanthera saxatilis is a little collected species apparently endemic to rocky sandstone formations in Chapada dos Guimarães, Mato Grosso state, Brazil. It differs from similar species by its perennial habit, lignotubers, isomorphic to slightly subisomorphic androecium, stamens positioned in a circle around the style during anthesis, antesepalous stamens with short connectives, small inconspicuous staminal appendages, and purple anthers. Photos of living specimens, a distribution map, scanning electron photographs of seeds and leaves, a preliminary conservation status assessment, as well as comments on vascular plant endemism at the Chapada dos Guimarães are provided.

ABSTRACT The state of Rio Grande do Sul (RS) is located in the extreme south of Brazil, within a transition region between the tropical and subtropical zones of South America that has been frequently affected by fluctuations in climate and vegetation over the last millennia. Palynomorphs preserved in sediments have provided excellent study material for paleoenvironmental reconstitutions of this region, as they reveal the source organisms and their respective environments over geological time. The present study was conducted to provide additional palynological reference material preserved in Quaternary sediments from the RS coastal plain for paleoenvironmental reconstruction studies. Here, we present taxonomic descriptions of pollen from 29 angiosperm taxa extracted along two Quaternary sedimentary profiles: the Pirataba forest profile (29° 15’ S 49° 51’W) and the Faxinal forest profile (29° 21’ S 49° 45’ W), Torres municipality, in the extreme north of the coastal plain of RS. Ecological data and pollen photomicrographs accompany the taxonomic descriptions. This reference material, together with the other palynomorphs found in the two sedimentary profiles, was the basis for our study of paleoenvironments from the last millennia in southern Brazil, according to the dynamics of climate and vegetation.

ABSTRACT Mikania is a pantropical genus of Asteraceae with ca. 450 species distributed mainly in South America. Although most of its species occur in forested phytophysiognomies, significant richness is found in the mountaintop grasslands known as campos rupestres in Brazil. Recent botanical exploration of campos rupestres areas outside their core distribution, namely Serra do Padre Ângelo, Pico da Aliança, and Sete Salões State Park, all located in the eastern part of the state of Minas Gerais and within the Atlantic Forest phytogeographic domain, led to the description of several new plant species. After fieldwork and study of herbarium specimens, we recognize two new species of Mikania endemic to Pico da Aliança and Serra do Padre Ângelo. Mikania semirii is related to Mikania phaeoclados and differs by leaf indumentum, subinvolucral bract shape and size and position on the peduncle. Mikania funkiae is related to Mikania glauca and Mikania obtusata, and differs by the petiole length, leaf shape, texture, and margins. We provide full descriptions, illustrations, distribution maps, composite color figures, preliminary conservation status assessments, and comments on the taxonomy and ecology of these two species. These findings highlight the continued importance of floristic and taxonomic work on the rich eastern Brazilian flora.

ABSTRACT Explaining where plants originated and how plants migrated between eastern Asia and other Northern Hemisphere regions is still challenging. The genus Arisaema is considered a good example to illuminate this process, due to its wide distribution in both the tropical and temperate zones. Based on comprehensive taxon sampling, the historical biogeography of Arisaema was conducted using the molecular data from four chloroplast DNA regions. The phylogeny of Arisaema was studied by using ML and BI methods. Divergence times of Arisaema species were estimated by the uncorrelated lognormal Bayesian method. The ancestral area reconstruction of Arisaema was performed with BioGeoBEARS and Bayes-DIVA. Our results indicated that the crown group of Arisaema originated in Southeast Asia ca. 31.28 Ma. After the initial origin, Arisaema was inferred to have become widespread in Southeast Asia. Members in Himalayas, Africa and North China, Japan, the Korean Peninsula region (NJK region) were derived from migrants originating in Southeast Asia. American members were derived from migrants originating in the NJK region. Arisaema originated in Southeast Asia during the Oligocene with the development of tropical rainforest and a warm, moist climate. During the Oligocene to Miocene, Southeast Asia was the original center for the diversification of Arisaema in the NJK region.

ABSTRACT Eremitis is one of the three genera of the subtribe Parianinae (Poaceae, Bambusoideae, Olyreae) and is restricted to the Atlantic Forest in eastern Brazil. Eremitis aemula, herein described and illustrated, is microendemic to the Alto Cariri State Park, located in the Baixo Jequitinhonha region, an area considered to be extremely important for conservation of the flora in the state of Minas Gerais. This new species is morphologically similar to Eremitis jardimii and E. robusta. However, E. aemula is differentiated from both species mainly by its longer decumbent culms (47-50 cm long vs. 22-25 cm and (15-)25-28 cm, respectively) with shorter inflorescences (4.5-5 cm long vs. 5.5-6 cm and 6-6.5 cm, respectively), and by its leaf blades with rounded base (vs. attenuate in E. jardimii and E. robusta). The total number of bamboos in Minas Gerais thereby rises to 79 species with 16 endemic to the state, reinforcing the fact that the Baixo Jequitinhonha is of extreme importance to the conservation of the Minas Gerais flora.

ABSTRACT Although the Araucaria Mixed Forest has long been recognized for their woods and ecosystem services, we still lack basic information on what tree species occur there. Habitat loss and overexploitation have led several tree species of this forest into an extinction process. Therefore, it is urgent to compile what are the tree species of this forest type, identify if these species are threatened and which were not assessed for their threat category. We aimed to answer: (1) How many tree species occur in the Araucaria Mixed Forest? 2) How many of these species are under a threat category? (3) Does the number of threatened species per state/province mirror the species richness of the state/province through the Araucaria Mixed Forest distribution? We found 1,213 tree species for the forest type. The states of São Paulo, Minas Gerais and Rio de Janeiro presented the highest species richness. The number of assessed species reflected the total number of species per state/province. Of the species listed, 5.3 % were classified as threatened and 72.8 % have not been assessed. We provided the most comprehensive tree species list to date for the Araucaria Mixed Forest and unveiled the conservation status of its tree flora.