ABSTRACT Climate influences species distribution and selects different morphological traits. The Chaco biome has climatic gradients, leading us to question morphological trait distribution. Using Fabaceae as a study model, we aimed to understand how the dispersal traits of this family, such as fruit types, dispersal syndromes and dispersal units, are distributed along the climatic gradients in the Chaco. We performed a spatial analysis in order to generate spatial predictors and thus identify on which spatial scales climate and soil variables are relevant to the distribution of the traits. Also, we used Threshold indicator rate analysis to identify the variation of the traits along the gradients. Temperature seasonality, precipitation seasonality, and annual mean precipitation are significant predictors of the distribution of the analyzed traits. Anemochory and barochory show the occurrence of reductions in intermediate gradient values for temperature seasonality. Regarding precipitation seasonality, craspedium showed greater reductions. At intermediate values of the rainfall gradient, we observed an increase in the occurrence of drupes and follicles. Craspedium increases in drier regions. Understanding the dispersion patterns of Fabaceae, a group of significant ecological and ethnological relevance in the Chaco, should contribute to the consolidation of conservation plans in different dry forest areas in South America. model family types units Also seasonality follicles regions America

Resumo Os domínios fitogeográficos são estruturados por diferentes fatores geoclimáticos (abióticos) tais como altitude, temperatura e precipitação. Assim, nosso objetivo foi investigar quais os possíveis fatores abióticos que estão relacionados à riqueza florística do componente arbóreo-arbustivo em remanescentes de Chaco, ao longo de sua extensão. O estudo é baseado em dados de presença e ausência de espécies em diferentes remanescentes relacionados com dados geoclimáticos. Somado a isso, foram utilizados shapes da World Wildlife Fund para diferir o Chaco seco do úmido. O banco de dados agregou 36 áreas e 522 espécies. A afinidade florística entre os grupos foi relacionada principalmente à temperatura, altitude e sazonalidade da precipitação. Em remanescentes onde a sazonalidade da precipitação e a altitude foram mais evidenciados, há maior dissimilaridade na composição da vegetação arbóreo-arbustiva. Por outro lado, o gradiente de temperatura explicou a homogeneidade florística no Chaco úmido. Assim, a riqueza do componente arbóreo-arbustivo do Chaco é atribuída principalmente a três fatores geoclimáticos. O Chaco seco apresenta maior dissimilaridade florística comparado ao Chaco úmido. Ainda, a sazonalidade da precipitação e a altitude têm papel preponderante na estruturação de árvores e arbustos no Chaco seco e a temperatura nas formações mais homogêneas que integram o Chaco úmido.

Abstract The phytogeographic domains are structured by different geoclimatic (abiotic) factors, such as altitude, temperature and precipitation. Thus, our goal was to investigate the possible abiotic factors that are related to the floristic richness of the tree-shrub component throughout the Chaco remnants. This study is based on data of the presence and absence of species in different remnants related to geoclimatic data. In addition, World Wildlife Fund shapes were used to differentiate dry and wet Chaco. The database aggregated 36 areas and 522 species. The different clusters obtained by floristic affinity between groups in Chaco was mainly related to temperature, altitude and seasonality of precipitation. In remnants where the seasonality of precipitation and altitude were more evident, there is greater dissimilarity in the composition of the tree-shrub vegetation. On the other hand, the temperature gradient explained the floristic homogeneity in the humid Chaco. Thus, the richness of the tree-shrub component of the Chaco is mainly attributed to three geoclimatic factors. Dry Chaco presents greater floristic dissimilarity compared to Humid Chaco. Still, the seasonality of the precipitation and the altitude play a dominant role in the structuring of trees and shrubs in the Dry Chaco and the temperature in the most homogeneous formations that integrate the humid Chaco.

ABSTRACT We investigated the influence of Quaternary climate fluctuations on the current distribution of three species of Leguminosae (Fabaceae) occurring in the Chaco. Potential distribution models of Bauhinia hagenbeckii, Muellera nudiflora and Neltuma rubriflora with a supposed endemism area were generated. The Last Interglacial, Last Glacial Maximum, Holocene Middle and current scenarios were used. The species showed a potential distribution according to the South American biogeographic history regarding the glacier regression and the formation of the Dry Diagonal. The models for each Quaternary event exhibited a tolerable AUC ≥ 0.9 for the validations. The LGM was the event that favoured the current species establishment areas in the Dry Diagonal. Quaternary climatic events were related to the current Leguminosae distribution. Bauhinia hagenbeckii and Neltuma rubriflora present similar areas of environmental suitability. Muellera nudiflora models with areas of environmental suitability were larger for the LIG and Holocene than for areas from other periods. All scenario models (LGM, HM and current scenario) highlighted the potential distribution of the three species concomitant with the glacier regression events and were consistent with the history of formation of South American dry areas.

ABSTRACT We characterized taxonomic and functional differences between two vegetation physiognomies in the Brazilian Chaco, namely chaco woodland (CW) and chaco forest (CF), in order to understand which abiotic and biotic mechanisms underlie the establishment of different physiognomies. We characterized the vegetation physiognomies by comparing woody species composition, richness and diversity and functional diversity between CW and CF plots. We also measured soil variables to characterize abiotic factors related to the different physiognomies. Species richness and diversity and soil nutrient values were higher in CF. Leaf succulence and nitrogen content were higher in CW, while height, leaf area, and specific leaf area were higher in CF. The standardized effect size (SES) of functional richness was higher in CW, but the SES of functional dispersion did not differ between CF and CW. We observed a diversity gradient related to soil fertility. Traits of species in CW were related to adaptations to poor soils, while in CF floristic composition showed a prevalence of species with more attributes related to competition for light. Thus, the structure of the floristic community in CW is likely related to an environmental filter, while competition for resources prevails in CF.

ABSTRACT The distributions of species of Fabaceae are strongly related to the soil. Their presence can alter restrictive conditions and favour the establishment of other species. However, it is still not known how the relationship between species of Fabaceae and edaphic factors interact in structuring woody Chaco vegetation. In this context, we aimed to test the hypothesis that restrictive edaphic conditions can explain the difference in floristic patterns of two types of vegetation through their species representativeness of Fabaceae. We analysed floristic consistency between wooded and forested Chaco to address how spatial and environment components might explain differences between them along with the effects of the interaction between Fabaceae and the soil. We observed that the association between environmental and spatial variables was more important than any individual factor in explaining the structuring of the communities. Both the percentage of species of Fabaceae present and the soil influence the structure of the two types of vegetation. Species of Fabaceae have greater potential as indicators in the wooded Chaco. Therefore, we suggest the interaction between soil types and species of Fabaceae plays a role during the structuring of the communities through the establishment of these species in more restrictive soils.

ABSTRACT Herbaria represent irreplaceable repositories of biodiversity and are used to answer questions about conservation, ecology, systematics, and other sciences. In this sense, we characterize the infrastructure, human resources, and idiosyncrasies of Brazilian herbaria. To achieve this goal, curators were sent a structured and standardized questionnaire to gather information about herbaria. The Brazilian Herbaria Network listed 216 active herbaria in the year 2018, of which 139 answered the questionnaire. These herbaria hold 6,741,469 samples in their collections and more than 39,000 type samples. Most herbaria are in federal universities (40.28 %). Only 24 % of the curators considered that their herbarium is valued by their institutions and 52 % indicated inadequate storage areas. Only nine collections have smoke sensors. Our analysis showed that if an herbarium has an institutional policy the curator is 78 % more likely to consider its herbarium valued. Therefore, it is important for all herbaria to institute their policy. These numbers reflect the difficulty in maintaining herbaria, in many cases cared for only by its curator without institutional recognition and support. Despite recent losses in Brazilian natural history collections, herbaria are still threatened by a lack of basic infrastructure.

Resumo O Chaco é maior domínio de florestas contínuas da América do Sul e agrega distintas famílias botânicas com destaque à Leguminosae. A elevada riqueza e diversidade de membros de Leguminosae, sobretudo de Papilionoideae, aliada à distribuição de determinados gêneros comuns às florestas secas tem motivado a investigação deste interessante grupo de plantas nas formações chaquenhas do Brasil. Este estudo florístico-taxonômico fornece chave de identificação, descrições morfológicas, ilustrações, comentários taxonômicos e ambientes preferenciais das espécies de Papilionoideae ocorrentes no Chaco do Brasil. Confirmamos a ocorrência de 45 espécies, distribuídas em 21 gêneros. Os gêneros com maior número de espécies são Aeschynomene (10), Galactia (4), Indigofera (4), Stylosanthes (4) e Desmodium (3). Os demais encontram-se representados por duas ou uma espécie: Arachis (2), Centrosema (2), Macroptilium (2), Rhynchosia (2), Amburana (1), Ancistrotropis (1), Camptosema (1), Crotalaria (1), Discolobium (1), Dolichopsis (1), Geoffroea (1), Machaerium (1) e Muellera (1), Sesbania (1), Tephrosia (1) e Zornia (1). Espécies dos gêneros Muellera, Dolichopsis e Geoffroea são exclusivas de áreas secas da América do Sul. Aeschynomene magna é registrada pela primeira vez para o Brasil, e considerada endêmica do Chaco. Stylosanthes maracajuensis é o primeiro registro para o Chaco.

Abstract The Chaco is the largest area of continuous forests in South America and assembles different botanical families with emphasis on Leguminosae. The high richness and diversity of Leguminosae members, especially from Papilionoideae, associated with the distribution of certain genera common to dry forests, have motivated the investigation of this interesting group of plants in Brazilian Chaco formation. This floristic-taxonomic study provides an identification key, morphological descriptions, illustrations, taxonomic comments and preferred environments of Papilionoideae species occurring in the Brazilian Chaco. We confirmed the occurrence of 45 species belonging to 21 genera. The genera with the largest number of species are Aeschynomene (10), Galactia (4), Indigofera (4), Stylosanthes (4) and Desmodium (3). The others are represented by two or one species Arachis (2), Centrosema (2), Macroptilium (2), Rhynchosia (2), Amburana (1), Ancistrotropis (1), Camptosema (1), Crotalaria (1), Discolobium (1) Dolichopsis (1), Geoffroea (1), Machaerium (1) and Muellera (1), Sesbania (1), Tephrosia (1) and Zornia (1). Species of genera Muellera, Dolichopsis and Geoffroea are unique to dry areas of South America. Aeschynomene magna is registered for the first time in Brazil and considered endemic to the Chaco. Stylosanthes maracajuensis is recorded for the first time for Chaco areas.

Resumen:La Serra de Maracaju yuxtapone los distintos tipos de vegetación de la floresta seca estacional y del cerradón (la fitofisiognomía del cerrado). Los dos tipos de vegetación son distintos en altura de copa, densidad de árboles y composición del sotobosque. Estas diferencias deben reflejarse en la composición de especies de plantas trepadoras que se encuentran en los dos tipos de bosque. Especies trepadoras de dos fragmentos forestales de la Serra de Maracaju han sido comparadas para responder: (1) ¿La riqueza de especies y composición florística de trepadoras es similar en el cerradón y en la floresta estacional decidua? (2) ¿Cuáles especies distinguen los dos tipos vegetacionales de otros? (3) ¿Los dos tipos vegetacionales difieren significativamente en mecanismo de ascensión, formas de vida y síndrome de dispersión en las especies trepadoras? Cuatro parcelas por tipo de floresta han sido muestreadas durante 24 meses. Las especies fueron identificadas y caracterizadas en tres rasgos discretos. Las diferencias proporcionales fueron analizadas usando el test chi-cuadrado. La riqueza y composición florística de trepadoras no fue similar en las dos formaciones: 37 especies en el cerradón y 31 en la floresta estacional decidua, con 13 especies compartidas. Dioscoreaceae, Fabaceae, Malpighiaceae y Sapindaceae corresponden al 60 % de las especies trepadoras. Las formaciones poseen características comunes como la forma de vida herbácea, el mecanismo de ascensión voluble y la anemocoria. La familia predominante fue Dioscoreaceae, no prevalente en estudios en Brasil. A pesar de la proximidad geográfica, la composición florística de los fragmentos de cerradón y de la floresta estacional decidua difiere substancialmente. Las características morfológicas de las especies no difieren estadísticamente, posiblemente por las condiciones climáticas uniformes y la fuerte similitud entre las composiciones florísticas de las familias.

Abstract:In the Parana basin, the Serra de Maracaju juxtaposes the Seasonal Dry Forest and the cerradão (a phytophysiognomy of Cerrado), two distinct vegetation types that differ in canopy height, tree density, and composition of the understory. In the same way, these differences may be reflected in the composition of climbing plant species found in these two forest types. Thus, in this study we compared the climbing species in two forest fragments of Serra de Maracaju to understand: (1) Are species richness and floristic composition of climbing plants similar in cerradão and seasonal deciduous forest?, (2) What degree of floristic compositional difference exists between the two vegetation types?, (3) Do the two vegetation types differ significantly in climbing mechanisms, life forms, and dispersal syndromes represented among climbing species? For this, we established and sampled four plots per forest type over 24 months. Species were identified and each one classified, based on three discrete traits. Proportional differences were analyzed using chi-square tests. Our results showed that species richness and floristic composition of climbing plants in the cerradão and the seasonal deciduous forest were not similar. Climber species richness in cerradão was 37 while in the seasonal deciduous forest it was 31; they share only 13 species. Four families, Dioscoreaceae, Fabaceae, Malpighiaceae, and Sapindaceae, included over 60 % of the climbing species. The morphological traits most common in both forest types were herbaceous life form, apical twining mechanism, and wind dispersal. Dioscoreaceae was found to be the dominant family, but is the first time to be reported for this condition in Brazil. Bignoniaceae and Passifloraceae ocurred only in the cerradão, and Asteraceae and Combretaceae in the seasonal deciduous forest; some species were found exclusively in a type of forest. Floristic composition of the cerradão and seasonal deciduous forest fragments were substantially different, in spite of physical proximity. However, their climbing species are not statistically distinct in morphological characteristics, possibly due to uniform climatic conditions and the similarity of species because of a shared ancestry (similar families). Rev. Biol. Trop. 65 (3): 1215-1225. Epub 2017 September 01.

Resumo Este estudo consiste no tratamento florístico-taxonômico de táxons de Mimosoideae ocorrentes no Chaco brasileiro. Os espécimes analisados são oriundos de coletas realizadas de 2004 a 2012, em remanescentes de Chaco localizados no sudoeste de Mato Grosso do Sul, no município de Porto Murtinho. Mimosoideae encontra-se representada por 39 táxons distribuídos em 14 gêneros. Dentre os gêneros mais representativos destacam-se Mimosa (16 táxons) e Prosopis (quatro táxons). Os registros de Chloroleucon chacoense, Mimosa centurionis e Prosopis alba no Chaco brasileiro configuram dados inéditos de ocorrência para a Flora do Brasil. Prosopis nigra tem com este estudo sua ocorrência ampliada. Mimosoideae é a segunda subfamília com elevada riqueza quando comparada às demais de Leguminosae estudadas no Chaco brasileiro. O estudo inclui descrições morfológicas, chaves de identificação, ilustrações e comentários taxonômicos.

Abstract This research consists of the taxonomic-floristic treatment of taxa of Mimosoideae occurring in the Brazilian Chaco. The specimens analyzed were collected from 2004 to 2012 in Chaco remnants located in southwestern Mato Grosso do Sul, Brazil. Mimosoideae is represented by 39 taxa belonging to 14 genera; among the most representative, Mimosa (16 taxa) and Prosopis (4 taxa) are highlighted. Chloroleucon chacoense, Mimosa centurionis and Prosopis alba are new records for the Brazilian Flora. Prosopis nigra has its occurrence expanded. Mimosoideae is the second subfamily in species richness compared with other subfamilies of Leguminosae studied in the Brazilian Chaco. This work includes morphological descriptions, identification keys, illustrations and taxonomic comments.

<p>The phytochemical investigation and evaluation of the phytotoxic effect of the extract and fractions obtained from the leaves of <italic>Annona nutans</italic>(R. E. Fr.) R. E. Fr. were performed. Phytotoxic activity was assessed on radicle and hypocotyl of <italic>Allium cepa</italic> and <italic>Lactuca sativa</italic>, where chloroform and ethyl acetate fractions proved active. Phytochemical investigation of the chloroform fraction was allowed identification of polyketides derivatives: triacontanal, 16-hentriacontane, octacosanol and triacontanol, using the ¹H NMR technique associated with data from GC/MS. Using ethyl acetate fraction, with low activity, flavonoids 3-<italic>O</italic>-β-D-galactopyranosyl-isorhamnetin, 3-<italic>O</italic>-β-D-galactopyranosyl-quercetin and 3-<italic>O</italic>-β-D-apiofuranosyl-(1→2)-galactopyranosyl-quercetin were identified, determined by spectrometric techniques one and two-dimensional NMR, combined with mass spectral data. All substances are being reported for the first time in <italic>Annona nutans</italic>. The phytotoxic activity of chloroform fraction may be related to the presence of triacontanol and similar substances. Triacontanol stimulates growth at very low concentrations, but can have an inhibitory effect at higher concentrations, such as those reported for auxin analogs. The toxicity assay using <italic>Artemia salina</italic> (BST) was also performed, with the chloroform fraction showing a negligible lethal dose, LD₅₀ = 500 mg mL^-1, while the other fractions and extracts showed no activity. Thus, the presence of acetogenins was ruled out.</p>

Neste estudo foram identificados os padrões de distribuição geográfica dos 102 táxons de Leguminosae ocorrentes no PEIT, com base nos dados obtidos na literatura e em material de herbário, sendo 38 exclusivos dos Campos Rupestres e 49 das Florestas Estacionais. Foram reconhecidos 11 padrões de distribuição geográfica, dos quais o padrão América do Sul Ocidental-Centro-Oriental foi o mais representativo com 27 táxons. Dos 102 táxons amostrados de Leguminosae, cinco são endêmicos da Cadeia do Espinhaço e 10 constam nas listas de espécies ameaçadas da flora brasileira ou da Flora de Minas Gerais, sendo consideradas importantes para fornecer subsídios na conservação das formações vegetacionais do PEIT.

This study identified patterns of geographic distribution of 102 Leguminosae taxa within the Park, based on literature data and herbarium specimens. Among the taxa, 38 grow exclusively in CamposRupestres (rocky fields) and 49 in the Semideciduous Forest. Eleven patterns of geographic distribution were identified, of which the West-East-Central South America pattern was the most representative, with 27 taxa. Of the 102 sampled taxa of Leguminosae, five are endemic to the Espinhaço Range and ten are included in lists of endangered species of the flora of Brazil and Minas Gerais. Information on these taxa is crucial to provide conservation practices for conserving the vegetation formations of the PEIT.

Rhynchosia, gênero pantropical, é constituído por 230 espécies distribuídas principalmente nos neotrópicos, considerado o centro de diversidade do grupo. Está relacionado filogeneticamente com o gênero Eriosema (DC.) Rchb., do qual se diferencia principalmente por características morfológicas. Em Mato Grosso do Sul está representado por oito táxons: Rhynchosia balansae Micheli var. balansae, R. balansae var. psilantha Fortunato, R. clausseni Benth., R. corylifolia Mart. ex Benth., R. edulis Griseb., R. leucophylla Benth., R. melanocarpa Grear e R. minima (L.) DC. O presente estudo apresenta chave de identificação, descrições, comentários, ilustrações, dados de distribuição geográfica e dos ambientes preferenciais de cada táxon.

Rhynchosia Lour. is a pantropical genus with 230 species, mainly distributed in the neotropics considered the center of diversity of the group. It is philogenetically related to the genus Eriosema (DC.) Rchb., from which it differs mainly through morphological characters. In Mato Grosso do Sul it is represented by eight taxa: Rhynchosia balansae Micheli var. balansae, R. balansae var. psilantha Fortunato, R. clausseni Benth., R. corylifolia Mart. ex Benth., R. edulis Griseb., R. leucophylla Benth., R. melanocarpa Grear and R. minima (L.) DC. The current study presents identification key, descriptions, comments, illustrations, data on geographic distribution and habitat preference of each taxon.

Este estudo consiste no inventário das Leguminosae-Papilionoideae do Parque Estadual das Várzeas do Rio Ivinhema (PEVRI), localizado ao sudeste de Mato Grosso do Sul e na investigação do hábito predominante das espécies nas diferentes formações do parque. As coletas incluindo todos os hábitos foram realizadas por meio de caminhadas, entre setembro de 2004 a setembro de 2009. O PEVRI agrega remanescentes de Floresta Estacional Semidecídua, de Floresta Estacional Semidecídua Aluvial e de campos. Foram registradas 23 espécies reunidas em 16 gêneros e 5 tribos com destaque para Phaseoleae com 7 gêneros, seguida por Dalbergieae com 6 gêneros e Desmodieae, Indigofereae e Crotalarieae representadas por 1 gênero cada. Dentre os 16 gêneros registrados destacaram-se como mais representativos: Crotalaria L. (4), Aeschynomene L. (3), Desmodium Desv. e Vigna Savi (2). As Papilionoideae herbáceas e subarbustivas predominaram em campo úmido e campo com pastagens, as arbóreas e lianas em Floresta Estacional Semidecídua. Nove espécies de Papilionoideae foram registradas em campo úmido, oito em Floresta Estacional Semidecídua e apenas uma em Floresta Estacional Semidecídua Aluvial. As Papilionoideae do PEVRI também foram registradas em outros estudos no Cerrado, Floresta Estacional Semidecídua e Pantanal, exceto Andira inermis, sem registros para a Floresta Semidecídua Aluvial.

This study aims to evaluate the richness of the Papilionoideae species found in the Parque Estadual das Várzeas do Rio Ivinhema (PEVRI), which is located in the southeast region of Mato Grosso do Sul, Brazil, and investigate if the habits of this Leguminosae group vary in different formations of the park. Monthly collections, including all habits, were made by walking along pre-established trails, from September 2004 to September 2009. The PEVRI includes Seasonal Semideciduous Forest, Seasonal Alluvial Semideciduous Forest and fields. Twenty-three species distributed in 16 genera and 5 tribes were recorded. Phaseoleae was noted with 7 genera, followed by Dalbergieae with 6 genera and Desmodieae, Indigofereae and Crotalarieae with only 1 genus in each species. Among the 16 recorded genera, Crotalaria L. (4), Aeschynomene L. (3), Desmodium Desv., and Vigna Savi (2) were the most representative. The Papilionoideae with herbaceous and subshrub habits were predominant in humid and pastures, while arboreous species and lianas were recorded in the Seasonal Semideciduous Forest. Nine species of Papilionoideae were recorded in humid grasslands, eight species in Seasonal Semideciduous Forest, and only one in Alluvial Semideciduous Forest. Papilionoideae found in the PEVRI have also been recorded in cerrado, Seasonal Semideciduous Forest and Pantanal, except Andira inermis, which does not present a reference for Seasonal Alluvial Semideciduous Forest.

O Cerrado é o segundo maior domínio morfoclimático brasileiro. O Cerrado é o segundo maior domínio morfoclimático brasileiro. Esta formação é rica em espécies, recebe influência dos domínios fitogeográficos circunvizinhos. O Cerrado, particularmente o cerradão, é vulnerável às mudanças de clima, solo e queimadas. Com base na avaliação da riqueza do estrato herbáceo do cerradão de uma RPPN urbana pretende-se responder as seguintes questões: Qual o hábito de crescimento, forma biológica e síndrome de dispersão predominantes? As espécies avaliadas são exclusivas do domínio fitogeográfico do Cerrado? As coletas foram realizadas de maio de 2007 a junho de 2008 em um remanescente de cerradão da RPPN/UFMS, Campo Grande, MS. Encontramos 59 espécies, 49 gêneros e 17 famílias. As famílias mais representativas foram Fabaceae (15 espécies), Poaceae (12) e Asteraceae (sete). Predominaram as herbáceas eretas (83%), hemicriptófitas (59%) e autocóricas (61%). Em relação à distribuição nos domínios fitogeográficos brasileiros observamos que 12% das espécies são exclusivas de Cerrado e 16% ocorrem no Cerrado, Amazônia, Caatinga, Mata Atlântica e Pampa.

The Cerrado is the second largest Brazilian morphoclimatic domain. It very rich in species, many endemic but it is also influenced by surrounding phytogeographic domains. The Cerrado, particularly cerrado woodland, is vulnerable to changes in climate and soil and to wildfires. Based on the avaliation of the richness of the herbaceous of the cerrado woodland of an urban RPPN want to answer the following questions: What is the growth habit, biological form and dispersal syndrome predominant? These species are exclusive of Cerrado phytogeographical domain? Samples were collected from May 2007 to June 2008 in a remnant of cerrado woodland on the RPPN/UFMS, Campo Grande, MS. We found 59 species, 49 genera and 17 families. The families most representative were Fabaceae (15 species), Poaceae (12) and Asteraceae (seven). Predominated the erect herbs (83%), hemicryptophyte (59%) and autochorich (61%). About distribution of species in Brazilian phytogeographic domains, 12% are exclusive to Cerrado and 16% are in Cerrado, Amazônia, Caatinga, Mata Atlântica and Pampa.

Resumo Neste estudo, são confirmados 18 táxons de Machaerium para Mato Grosso e Mato Grosso do Sul. Dos 15 táxons ocorrentes em Mato Grosso, seis são citados pela primeira vez no Estado: M. biovulatum, M. floribundum var. floribundum, M. macrophyllum var. macrophyllum, M. paraguariense, M. quinatum var. parviflorum e M. quinatum var. quinatum. Das nove espécies ocorrentes no Mato Grosso do Sul, M. eriocarpum e M. isadelphum são novas ocorrências para o Estado. O gênero encontra-se amplamente distribuído nos Estados e está representado em diversas formações vegetacionais. São apresentadas chave analítica, descrições e informações sobre a fenologia e os ambientes preferenciais de cada táxon, além de ilustrações para determinados táxons.

Abstract In this study, 18 taxa of Machaerium are confirmed for Mato Grosso and Mato Grosso do Sul. Amongst the 15 taxa occurring in Mato Grosso, six were cited for the first time in the State: M. biovulatum, M. floribundum var. floribundum, M. macrophyllum var. macrophyllum, M. paraguariense, M. quinatum var. parviflorum, and M. quinatum var. quinatum. Amongst the nine species confirmed for Mato Grosso do Sul, M. eriocarpum and M. isadelphum are new records for the State. The genus is widely distributed in the States and is represented in various vegetational formations. Analytical key, descriptions, and information on the phenology and preferential environments of each taxon are presented, besides illustrations for certain taxa.