Resumo em Inglês:

Abstract We describe and illustrate Paepalanthus magistrae, a remarkable new species of Eriocaulaceae from Northeastern Brazil. The species is placed into Paepalanthus subsect. Dichocladus by the presence of trimerous flower, elongated dichotomous branched stem, and small rigid leaves. Within the section it may be easily distinguished by its leaves with glabrescent adaxial surface and lanose abaxial surface. As the species is narrowly distributed and known from a few populations, it is considered endangered.

Resumo em Inglês:

Abstract Poales represents a major part of Angiosperm and Monocot diversity. The families encompass ca. 20,000 species which is about 7% of the Angiosperms and 33% of the Monocots. Bromeliaceae, Cyperaceae, Eriocaulaceae, Juncaceae, Mayacaceae, Poaceae, Rapateaceae, Thurniaceae, Typhaceae, and Xyridaceae are the families represented in the Neotropics. In general terms some areas in the Neotropics could be considered hotspots for Poales with a high number of species in several genera and several centers of endemism – the Guayana Shield, Espinhaço Range and Atlantic Forest are highly diverse in Poales. In terms of the Brazilian flora, the order is well represented in the entire country with almost 4,400 species. It represents more than 50% of the total number of species of Monocotyledons in Brazil. The main goal here is to summarize the available information and provide an overview of the Poales in the Neotropics. The state of knowledge for each family, focused on the Brazilian flora, is provided and reinforces the importance of new studies in key-groups looking beyond the understanding of their diversity on the continent but also the conservation of the species.

Resumo em Inglês:

Abstract Current phylogenetic hypotheses support that ancestral Poales were animal-pollinated and that subsequent shifts to wind pollination have occurred. Ten of the 16 Poales families are widely distributed in the Neotropics, however a comprehensive understanding of their pollination systems' diversity is still lacking. Here we surveyed studies on pollination biology of Neotropical species of Poales. Poaceae, Cyperaceae and Juncaceae are predominantly wind-pollinated but insect pollination also occurs. Thurniaceae and Thyphaceae fit on anemophily but empirical data are missing. Pollen flowers with poricidal anthers have evolved independently in Mayacaeae and Rapateaceae. Pollen- and nectar-flowers occur in Xyridaceae, which are mainly pollinated by bees. Eriocaulaceae flowers secrete minute quantity of nectar and are pollinated by "diverse small insects". Pollination of Bromeliaceae is carried out by a great variety of animal groups, mainly hummingbirds, and includes anemophily. The diversity in floral forms is very high within the order but more constant within the families. This trend indicates that many events of species diversification may have occurred without divergence in the pollination mode. Still, parallel shifts in pollination modes are found, including possible reversals to wind- or animal-pollination, changes in the type of pollinators (e.g. from hummingbirds to bee or bats) and the arising of ambophily.

Resumo em Espanhol:

Resumen Análisis de diversidad de la familia Poaceae en la región austral de América del Sur. La familia Poaceae es una de las mejor representadas en América del Sur austral, con un total de 206 géneros que comprenden 1523 especies distribuidas en 10 subfamilias diferentes. En este trabajo analizamos la distribución de estos grupos en Argentina, sur de Brasil (Paraná, Rio Grande do Sul y Santa Catarina), Chile, Paraguay y Uruguay; discutimos la riqueza de las diferentes subfamilias, tribus y géneros, su distribución, especies endémicas, la relación de especies anuales y perennes, así como el número de especies Kranz y no Kranz, su abundancia según regiones geográficas, en relación con la temperatura y las precipitaciones, géneros disyuntos, y la proporción de taxones en relación con las diferentes.

Resumo em Inglês:

Abstract Analysis of Poaceae biodiversity in austral South America. The Poaceae is one of the best represented families in austral South America with a total of 206 genera comprising 1523 species arranged in 10 different subfamilies. Here we analyzed the distribution of these taxa in Argentina, southern Brazil (Paraná, Rio Grande do Sul and Santa Catarina), Chile, Paraguay, and Uruguay; we discuss the species richness of the different subfamilies, tribes and genera, its distribution, endemics, annual and perennial species as well as Kranz and non Kranz taxa, its geographical distribution in relation to temperature and rainfall, disjunct genera, and proportion of taxa in relation to the different ecoregions in the area.

Resumo em Inglês:

Abstract Scleria is the fifth largest genus of Cyperaceae, and the third most diverse genus of Cyperaceae in Brazil. In Santa Catarina the floristic account of Cyperaceae is in need of updating, particularly as the Atlantic forest, home to many species of Scleria, is one of the most threatened environments worldwide. Scleria is thus a leading candidate for an updated floristic account, particularly so as to identify the conservation status of its species within the remaining natural vegetation. The survey has confirmed thirteen taxa including a new subspecies, S. georgiana ssp. australis, here described. Scleria sellowiana is lectotypified here. A species identification key, morphological descriptions, geographic distributions, global conservation status according to IUCN Red List criteria, habitats, phenological aspects, taxonomic notes and illustrations are provided for each species.

Resumo em Inglês:

Abstract Pleurostachys Brongn. is a Neotropical genus of Cyperaceae closely related to Rhynchospora Vahl. It is found in the Atlantic and Amazon Forests from northern South America to southern Brazil and most of the species grow in the humid and shady understory. Fourteen species are confirmed, 11 of them are endemic to the Brazilian Atlantic Forest and six are considered under the conservation status of Vulnerable. New synonyms and lectotypes are also indicated.

Resumo em Inglês:

Abstract (Hypolytrum (Cyperaceae): taxonomic and nomenclatural notes, geographical distribution and conservation status of Neotropical species.) Hypolytrum (Mapanioideae) is a medium-size and Pantropical genus of Cyperaceae, closely related to Mapania, Principina, and Scirpodendron. In the Neotropics, it is found from southern Mexico to southern Brazil where it grows in the Atlantic and Amazon Forests and Cerrado vegetation. Most of the species are found in the humid and shady understory of forested habitats. Twenty-nine species are confirmed, nine of which are considered narrow-endemics and one is poorly known. Twelve species are classified under the conservation status of Critically Endangered or Vulnerable. A total of 130 types (holo- types, isotypes, lectotypes and isolectotypes) and 42 photos of types were checked and confirmed, and 22 synonyms were verified and accepted. Information about geographic distribution including new occurrences, habitat and diagnostic characters are also provided.

Resumo em Português:

Resumo Paepalanthus Mart. (Eriocaulaceae) conta atualmente com cerca de 400 espécies, distribuídas principalmente nas Américas Central e do Sul, com centro de diversidade localizado na Cadeia do Espinhaço, em Minas Gerais e Bahia. É o gênero de Eriocaulaceae mais complexo do ponto de vista taxonômico e a carência de estudos florísticos dificulta o aprimoramento de sua circunscrição. Nesse contexto, foi efetuado o levantamento de Paepalanthus do Parque Estadual do Biribiri, que está inserido no Planalto de Diamantina, Minas Gerais. O gênero está representado no Parque por 33 espécies. É apresentada uma chave de identificação, descrições e ilustrações, bem como comentários sobre morfologia, habitat, distribuição geográfica e fenologia.

Resumo em Inglês:

Abstract Paepalanthus Mart. comprises approximately 400 species, mainly distributed in South and Central America, with center of diversity located in the Espinhaço Range, in Minas Gerais and Bahia. In a taxonomic point of view, Paepalanthus is the most complex genus of Eriocaulaceae and the lack of floristic studies hinders the improvement of its circumscription. In this context, it was carried out the Paepalanthus flora of Biribiri State Park, which is located in Diamantina Plateau, in Minas Gerais state. In the area, the genus is represented by 33 species. Identification key, descriptions and illustrations, as well as comments about morphology, habitat, geographic distribution and phenology are presented.

Resumo em Inglês:

Abstract Mayacaceae Kunth is an aquatic plant family that currently comprises a single genus, and four to six accepted species. Most of them are widely distributed in the Neotropics, with the exception of Mayaca baumii Gürke, which is endemic to Africa. This family still encompasses taxonomical problems involving mostly nomen- clatural issues and the positioning of the family within the Poales, which remains not definite, though several efforts have being made in this direction. Besides all this, the family also suffers from limited studies with different approaches, such as embryological, palinological, phylogenetic and ecological ones. Considering all this problems, the present work make an overview of Mayacaceae to show the main problems that still surround the family and to indicate some directions for future studies.

Resumo em Inglês:

Abstract Vriesea, with about 280 species distributed in two sections, Vriesea and Xiphion, is recognized as polyphyletic. We provide the cladistic analysis based on morphological data, with emphasis on species from eastern Brazil, its main center of diversity, which emerged as a monophyletic group in previous molecular and combined analysis. The data matrix contained information of 60 species of Vriesea, and two of Alcantarea, for a total of 62 terminal taxa and 66 characters. The analysis produced one tree with 652 steps. The classic infrage- neric division of the sections was not corroborated. Characters traditionally used to separate the two sections supported clades containing species from both sections. Morphologically related monophyletic groups were recognized. Some characters have been highlighted as potentially important in the circumscription of small groups of species and have not yet been much used in the systematics of Vriesea.

Resumo em Português:

Resumo Este trabalho foi baseado na análise de materiais de herbário, documentações bibliográficas e coletas, abran-gendo todos os ambientes de uma área da planície litorânea do Sul do Rio Grande do Sul. Foram registrados 39 táxons específicos e infra-específicos distribuídos em 14 gêneros. Destes, os mais representativos foram Cyperus L., com 11 táxons e Eleocharis R. Br, com 10. São fornecidas chaves para identificação de gêneros e espécies e comentários sobre aspectos morfológicos, habitat, distribuiçãoe fenologia.

Resumo em Inglês:

Abstract This work was based on analysis of herbarium materials, bibliographic documentation and collections, covering all environments from an area of the coastal plain of the southern Rio Grande do Sul. We recorded 39 specific and infra-specific taxa distributed in 14 genera. Of these, the most representative were Cyperus L. with 11 taxa and Eleocharis R. Br., with 10.Keys are provided for identification of genera and species and comments on morphological aspects, habitat, distribution and phenology.

Resumo em Português:

Resumo Apresenta-se neste trabalho um inventário das espécies de Bromeliaceae da Volta Grande do Xingu (Pará, Brasil), sendo também fornecida uma chave para identificação das espécies da região, e seus respectivos status de conservação quando existentes. O material utilizado foi obtido através das atividades do Projeto Salvamento e Aproveitamento Científico da Flora da Usina Hidrelétrica de Belo Monte, bem como na coleção do herbário MG. Na área de estudo, Bromeliaceae encontra-se representada por 20 espécies e sete gêneros. Tillandsia e Aechmea foram os mais representativos.

Resumo em Inglês:

Abstract In this paper is showed a checklist of the species of Bromeliaceae of the Volta Grande do Xingu (Pará, Brazil), where is provided a identification key for the region species, and your respective status of conservation when available. The material used in this study was obtained through the activities of the Project Rescue and Scientific Utilization of the Flora of the Belo Monte hydroelectric dam, executed by Norte Energia S.A and in the collection of herbarium MG. In the study area, Bromeliaceae is represented by 20 species and seven genera. Tillandsia and Aechmea were the most representative.

Resumo em Português:

Resumo Vriesea é o segundo maior gênero de Tillandsioideae com 281 espécies, distribuído predominantemente na América do Sul. No Brasil, as espécies ocorrem no Cerrado, na Amazônia, na Caatinga, Pampa e principalmente na Mata Atlântica, bioma com a maior riqueza específica do gênero. Na sistemática atual, Vriesea está dividido em duas secções, Vriesea e Xiphion. Na secção Xiphion enquadra-se grande parte do grupo V. platynema com 41 espécies, ocorrendo desde a América Central até a Argentina. O grupo apresenta acentuado polimorfismo, proporcionando a identificação errônea dos táxons. Neste estudo, são reconhecidos três táxons para o Paraná, V. platynema var. platynema, V. platynema var. variegata e V. tijucana. Para cada táxon, são apresentadas descrições morfológicas, comentários, chave de identificação, distribuição geográfica, ilustrações e o status de conservação.

Resumo em Inglês:

Abstract Vriesea is the second largest genus in Tillandsioideae with 281 species, distributed mainly in South America. In Brazil, occur at Cerrado, Amazon, Caatinga, Pampa and mainly in the Atlantic Rain Forest biome with the highest species richness of the genus. In the current systematic, Vriesea is divided into two sections, Vriesea and Xiphion. The section Xiphion is the largest of the group V. platynema with 41 species, occurring from Central America to Argentina. It has a high polymorphism, leading to misidentification of taxa. In this study, three taxa are recognized to Paraná State: V. platynema var. platynema, V. platynema var. variegata and V. tijucana. Descriptions, comments, key identification, geographical distribution, conservation status and illustrations are presented.

Resumo em Inglês:

Abstract Herein we present a taxonomic synopsis of Aechmea species from Alagoas, Pernambuco, Paraíba, Rio Grande do Norte and Ceará states. The lack of a taxonomic key for identification of species, the high rate of endemism and the recent novelties published within Aechmea from this region motivated this work. Samplings were conducted in areas of all states studied between 2010 and 2014. We identified 27 species in the study areas while two names were excluded from the species list compiled from the literature. The subgenus Aechmea was the most representative with 20 species. Of particular importance was the Gravisia complex, represented by ten of the 14 species that form this informal taxonomic group. Pernambuco and Alagoas were the most species-rich compared to the other states. For each species found in the study area, we present identification keys, comments on the taxonomic relationships, habitat information and geographical distribution.

Resumo em Português:

Resumo São registradas pela primeira vez para a flora do estado do Rio Grande do Sul (Brasil) Tillandsia loliacea Mart. ex Schult.f. e Tillandsia pohliana Mez, sendo também redescoberta Tillandsia bandensis Baker neste estado e Brasil. São fornecidas descrições, fotografias e dados de suas distribuições geográficas.

Resumo em Inglês:

Abstract In this short note are recorded for the first time for Rio Grande do Sul (Brazil) Tillandsia loliacea Mart. ex Schult.f. and Tillandsia pohliana Mez, and Tillandsia bandensis Baker was rediscovered in the same state and Brazil. We provide descriptions, photographs and geographical distribution for the species.

Resumo em Português:

Resumo É descrita e ilustrada Dyckia pontesii, uma nova espécie de Bromeliaceae (Pitcairnioideae) do Rio Grande do Sul (Brasil). São fornecidos dados sobre seu hábitat, ecologia, distribuição geográfica e afinidades mor- fológicas, sendo também avaliado o seu status de ameaça segundo os critérios da IUCN.

Resumo em Inglês:

Abstract Dyckia pontesii, a new species of Bromeliaceae (Pitcairnioideae) to Rio Grande do Sul (Brazil) is described and illustrated. Data on habitat, ecology, geographical distribution, morphological affinities and evaluation about its threat of extinction according to the criteria of the IUCN are provided.

Resumo em Inglês:

Abstract Bromelia includes 66 species, grouped in three subgenera: Bromelia, Distiacanthus and Karatas. The genus is one of the earlier divergent groups within Bromelioideae, a subfamily with innumerable problems of generic delimitation. Considering that few phylogenetic studies have included more than one species of Bromelia, the objectives of this study were to carry out a phylogenetic analysis for the genus, seeking to evaluate its monophyly as well as its subgenera, and to better understand the interspecific evolutionary relationships within the genus and the intergeneric relationships within Bromelioideae. Also included in the analysis were the two species of Fernseea, a genus originally described from a species placed in Bromelia. The phylogenetic analysis was conducted with combined micro- and macromorphological data, including 39 taxa with 116 characters. As in other studies on Bromeliaceae, the clades have low statistical support and many questions regarding the relationships of the groups remain. The circumscription of Bromelia is still uncertain, due to the position of B. irwinii; Fernseea seems to emerge within this genus, as the marority-rule consensus suggests, and the infrageneric categories are debatable because they do not constitute monophyletic groups. However, Bromelia seems to be paraphyletic and, without B. irwinii, the genus can be considered monophyletic. Beginning with the premise that the most recent common ancestor of Bromelioideae appeared first in the southern Andes, Bromelia and Fernseea seems to have dispersed along three biogeographical routes. The present work is an important contribution to understand the evolution and biogeography of the Bromelioideae.

Resumo em Inglês:

Abstract A taxonomic treatment of the Xyridaceae in the Viruá National Park is presented. Located in Roraima state, northern Brazil, the park comprises a mosaic of lowland vegetation types, including forests, wetlands, and one of the largest continuous areas of campinarana in the Brazilian Amazon Basin. Xyridaceae are represented in the park by 20 species in the genera Abolboda and Xyris. Although the four species of Abolboda are widespread, most of the Xyris species (75%) are endemic to Amazonian open vegetation formations, such as campinaranas and savannas. This study was based on field, herbarium, and scanning electron microscopy research. The taxonomic treatment includes identification keys to the genera and species, morphological descriptions, SEM images of seeds for Xyris species, iconography, geographic distribution and comments on the ecology of the species. The poorly known Xyris connosepala is synonymized in Xyris guianensis.

Resumo em Português:

Resumo O Parque Nacional da Serra dos Órgãos (PARNASO) constitui um dos maiores remanescentes de Mata Atlântica no estado do Rio de Janeiro. Bromeliaceae possui neste bioma um dos seus principais centros de diversidade, com 31 gêneros e 803 espécies, sendo mais de 500 pertencentes à subfamília Bromelioideae. Como parte do projeto Bromeliaceae organensis desenvolvido no Departamento de Botânica do Museu Nacional- UFRJ, o presente trabalho buscou inventariar as espécies de Aechmea, Billbergia, Hohenbergia e Quesnelia no PARNASO, fornecendo a descrição morfológica das espécies e uma chave para identificação, além de dados sobre sua distribuição, geral e dentro do parque. O estudo taxonômico foi realizado através da análise de material herborizado, coletas e observações de campo. Foram encontradas no parque: seis espécies de Aechmea, cinco de Billbergia, uma de Hohenbergia e quatro de Quesnelia. Apesar de bem representado em número de espécies na unidade de conservação, Billbergia conta com poucos registros nos herbários, sendo quatro de suas espécies referenciadas por um ou poucos indivíduos nas coleções. A localidade guarda ainda populações de espécies endêmicas do estado do Rio de Janeiro, como A. wellbachii, A. fasciata, Q. lateralis e Q. edmundoi var. edmundoi.

Resumo em Inglês:

Abstract The Serra dos Órgãos National Park (PARNASO) constitutes one of the largest remnants of the Brazilian rainforest in Rio de Janeiro state. In this biome, Bromeliaceae has one of its main centers of diversity, with 31 genera and 803 species, being more than 500 belonging to the subfamily Bromelioideae. As a part of the project Bromeliaceae organensis in development in the Departament of Botany of the Museu Nacional- UFRJ, the present work aims to inventory the species of Aechmea, Billbergia, Hohenbergia and Quesnelia on PARNASO, providing the morphological description of the species and an identification key, in addition to data about its distribution, general and inside the park. The taxonomic study was carried on through the analysis of the dried specimens, collections and field observations. Six species of Aechmea, five of Billbergia, one of Hohenbergia and four of Quesnelia, were revealed. Although well represented in number of species, Billbergia counts with a poor number of herbarium records, with four of them referenced by one or little more individuals in the collections. The locality also houses populations of endemic species of Rio de Janeiro state, like A. wellbachii, A. fasciata, Q. lateralis and Q. edmundoi var. edmundoi.

Resumo em Inglês:

Abstract Cyperus is a Pantropical genus and the second richest in species in Cyperaceae. It encompasses about 550 species worldwide, with about 100 of these occurring in Brazil. Studies on the taxonomy of this genus are scarce and punctual in Brazil. In this study, the occurrence of species was surveyed through 27 collecting expeditions across different regions in the state of Rio Grande do Norte and analyzis of specimens of several herbaria. Twenty four species of Cyperus were identified, including six new occurrences and one new species, here described, but that will be properly published in other work. This study includes a dichotomous key for the identification of the species, as well as illustrations, descriptions, taxonomic comments and geographical distribution.

Resumo em Português:

Resumo Este estudo compreende o levantamento taxonômico da subfamília Panicoideae (Poaceae) ocorrente no município de Ilha Grande, Piauí, Brasil. Foram registradas 17 espécies e 11 gêneros distribuídos na tribo Paniceae, 14 das espécies são novos registros para o Estado do Piauí. O gênero mais representativo foi Paspalum com cinco espécies. Axonopus compressus (Sw.) P. Beauv., é a única endêmica do Brasil e Paspalum vaginatum Sw. é utilizada para contenção de dunas. São apresentadas chaves para identificação das espécies, descrições, ilustrações, dados de distribuição e habitat.

Resumo em Inglês:

Abstract This study consists of a taxonomic treatment of the subfamily Panicoideae (Poaceae) in the municipality of Ilha Grande, Piauí State, Brazil, part of the Delta of the Rio Parnaíba. We recorded 17 species and 11 genera in tribe Paniceae, 14 of the species are new records for the state of Piauí. The largest genus is Paspalum with five species. Axonopus compressus (Sw.) P. Beauv. is the only species endemic to Brazil and Paspalum vaginatum Sw. is notable for its use in stabilizing sand dunes. An identification key, descriptions of all species, illustrations and notes on distribution and habitat of the species are provided.

Resumo em Inglês:

Abstract Two new species of Cyperus L. (Cyperaceae), both from Brazil, are described and compared to near relatives. Cyperus hooperae is described from two collections from the Chapada do Veadeiros in the State of Goiás; it is most similar to C. refractus of the southeastern U.S. Cyperus thomasii is described from a single collection from the municipality of Caruaru in Pernambuco; it is most similar to C. granatensis of Colombia. Following IUCN standards, both are considered threatened.

Resumo em Português:

Resumo As microestruturas da epiderme foliar são consideradas de grande valor na taxonomia de vários grupos de Cyperaceae e a deposição da sílica é um dos aspectos considerados de maior relevância. Uma proporção variável das células epidérmicas apresenta corpos silicosos, quase sempre com formato cônico e, relacionados, às regiões costais da folha. Os corpos silicosos podem ter formatos diferentes, como os conglomerados de sílica. Nas espécies aqui analisadas, a sílica é observada formando cones, conglomerados e também, impregnando as paredes das células epidérmicas, inclusive, dos estômatos e dos tricomas. Com base nas informações obtidas conclui-se que os caracteres anatômicos da epiderme das brácteas em espécies de Scleria ocorrentes na Serra do Cipó oferecem alguns subsídios, como o formato dos corpos silicosos, a distribuição dos estômatos e a presença ou ausência de tricomas (curtos e longos), que podem ser utilizados como caracteres diagnósticos para delimitação taxonômica.

Resumo em Inglês:

Abstract The leaf epidermis microstructures are considered of great value in several Cyperaceae groups taxonomy and the silica deposition is one of the aspects with great relevance. A variable proportion of the epidermis cells presents silica bodies, almost always with conical shape and, related to the leaf costal areas. The silica bodies assume different shapes as the silica conglomerates. In the species analyzed, the silica forms cones, conglomerates and also, appears impregnating the epidermis cell walls, including stomata and hairs. Based on this paper information, the bracts epidermis in the studied species of Scleria offers some subsidies, like silica bodies shape, stomata distribution and presence or absence of hairs (short and long) that can be used as diagnostic characters in taxonomic delimitation.

Resumo em Inglês:

Abstract In Cyperaceae about 1/3 of the species have Kranz anatomy and some species of Eleocharis can either present Kranzanatomy or not according to the environmental conditions, whether terrestrial (emerged) or aquatic (partly or fully submerged). Eleocharis minima has emerged and submerged scapes in the same individual. To identify the possible differences and their correlation with the environment, the anatomy of these scapes was investigated. The emerged scape is quadrangular e has four vascular bundles, and the submerged is triangular with three bundles. Both scapes (emerged and submerged) show non-Kranz anatomy in the basal region and Kranz anatomy of the eleocharoid type in the median region. In the apical region of submerged scapes occur Kranz anatomy of eleocharoid types, but in this same region of the emerged scape was observed variations in the continuity of the inner bundle sheath and may be interpreted as eleocharoid or chlorocyperoid types. The plasticity of the Kranz anatomy in Eleocharis minima and in other species of the genus is probably related to the amphibious habit. Therefore, the use of characters related to Kranz anatomy in Eleocharis in phylogenetic and evolutionary approaches should be restricted and carefully analyzed in view of its plasticity.

Resumo em Inglês:

Abstract An overview about ultrastructure of Kranz anatomy in Cyperaceae (Poales) - The ultrastructure of the Kranz tissues in Cyperaceae species with the four types of Kranz anatomy (chlorocyperoid, eleocharoid, fimbristyloid and rhynchosporoid) was studied and compared with species already described in the literature, with the goal verifying the occurrence of patterns for the Kranz types. In addition, chloroplasts and mitochondria were quantified for the first time for all Kranz types. The chloroplast’s structure is similar in the mesophyll cells (PCA) in the four Kranz types, but differs in some features in the bundle sheath cells (PCR). In the chlorocyperoid and rhynchosporoid types the bundle sheath cells (PCR) present centrifugal or scattered chloroplasts with convoluted or parallel thylakoids. In the eleocharoid types, the chloroplasts are scattered with parallel thylakoids. The fimbristyloid type presents centrifugal chloroplasts with convoluted and parallel thylakoids. To eleocharoid and fimbristyloid types and to Cyperus and Pycreus (chlorocyperoid) was observed pattern in the chloroplasts position. In most of the studied species the number of mitochondria in the bundle sheath cells (PCR) is significantly higher than in the mesophyll cells (PCA) and this result diverges from the results found in previous studies.

Resumo em Inglês:

Abstract Mesosetum is a Neotropical genus with 25 species, and 21 of them occur in Brazil. Mesosetum forms a clade closely related with Keratochlaena rigidifolia and Tatianyx arnacites. The objective of this work was to establish the taxonomic value of the upper anthecium micromorphology for the group. A total of 96 specimens, representing all Mesosetum species (except M. wrightii), K. rigidifolia and T. arnacites were examined under a scanning electron microscope (SEM). PCA and UPGMA analysis were applied using the micromorphologicalcharacters. Fifithteen useful taxonomic characters were identified. We highlight the following characters to distinguish the Mesosetum species: the presence, type and distribution of papillae on the abaxial surface of the upper lemma; the presence of unicellular macrohairs and bicellular microhairs; presence or absence of silica cells and the structure of the germination lid. The present work shows that the micromorphological characters identified are important taxonomically at the specific level, allowing the species identification in many cases.

Resumo em Inglês:

Abstract Nomenclatural correction in Cryptanthus Otto & A. Dietrich. (Bromeliaceae - Bromelioideae). A nomenclatural correction of the author name of Cryptanthus zonatus, an endemic species of Northeastern Brazil, is provided. A new synonym of this species is also proposed.