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ABSTRACT A taxonomic synopsis of Cypella (Iridaceae) in Brazil is presented with recognition of 16 species, two of them represented by two subspecies. An identification key to the taxa is provided and species are described and illustrated. New synonyms are indicated, and eight lectotypes, two epitypes and one neotype are designated. Results include distribution, habitat, phenology, conservation status, notes and examined specimens of all taxa, as well as comments on dubious and misused names. The resulting framework revealed that most of the Brazilian species of Cypella occur in the state of Rio Grande do Sul and in the Pampa Biome, although Río de la Plata grasslands (RPG) is the most species-rich biogeographic unit of the genus.

Abstract Sisyrinchium is the largest genus of Iridaceae in the Americas and has the greatest amount of cytological data available. This study aimed at investigating how genomes evolved in this genus. Chromosome number, genome size and altitude from species of sect. Viperella were analyzed in a phylogenetic context. Meiotic and pollen analyses were performed to assess reproductive success of natural populations, especially from those polyploid taxa. Character optimizations revealed that the common ancestor of sect. Viperella was probably diploid (2n = 2x =18) with two subsequent polyplodization events. Total DNA content (2C) varied considerably across the phylogeny with larger genomes detected mainly in polyploid species. Altitude also varied across the phylogeny, however no significant relationship was found between DNA content changes and altitude in our data set. All taxa presented regular meiosis and pollen viability (> 87%), except for S. sp. nov. aff. alatum (22.70%), suggesting a recent hybrid origin. Chromosome number is mostly constant within this section and polyploidy is the only source of modification. Although 2C varied considerably among the 20 taxa investigated, the diversity observed cannot be attributed only to polyploidy events because large variations of DNA content were also observed among diploids.

Sisyrinchium micranthum Cav. is a member of the family Iridaceae, which is distributed over the American continent. In Brazil, this species is found, not only in disturbed areas and coastal regions, but is also very common in urban centers, such as public parks, during the spring. Chromosome counts for North American specimens are 2n = 32 and 2n = 48, whereas in southern Brazil, there is a polyploidy series with three chromosome numbers, 2n = 16, 2n = 32, and 2n = 48. Population analyses using DNA molecular markers are inexistent for this species, in spite of its wide distribution and morphological variation. To study the genetic population structure of S. micranthum, five natural populations were accessed in a conservation park within the Atlantic Rain Forest Biome in southern Brazil. Here, the chromosome numbers 2n = 16 and 2n = 48 had already been described. Molecular analysis showed that the populations are highly structured with low gene flow among them. The population with 2n = 48 was genetically less variable than and distinct from the other populations. Population genetics in relation to cytogenetic data provided new insights regarding the genetic diversification and mating system of S. micranthum.

Plants of the family Iridaceae are well represented in the grassland vegetation of southern Brazil, occurring in the Pampa and Atlantic Forest biomes. Nevertheless, little is known about the taxonomy and evolution of Iridaceae species in southern Brazil. The main goal of this review is to compile published information about South American Iridaceae, and to discuss the evolution and genetic diversity of the family presenting our own research data in the light of the published literature. The main focus is on the genera Calydorea, Cypella, Herbertia, and Sisyrinchium. Aspects of reproductive system and of pollinator attraction are also discussed.

Foi realizado o levantamento florístico das espécies de Cyperaceae do Centro de Pesquisa e Conservação da Natureza PróMata (CPCN Pró-Mata), Rio Grande do Sul. O local de estudo está situado no município de São Francisco de Paula, na região fisiográfica dos Campos de Cima da Serra. Foram efetuadas cinco expedições de coleta e encontradas 42 espécies, distribuídas em oito gêneros. São apresentadas a lista das espécies, chaves de identificação nos níveis genérico e específico e fotomicrografias em Microscopia Eletrônica de Varredura dos aquênios de cada espécie.A floristic survey of Cyperaceae species at the Centro de Proteção e Conservação da Natureza Pró-Mata (CPCN Pró-Mata), Rio Grande do Sul was performed. The study area is located in São Francisco de Paula municipality, in the physiographic region of the Campos de Cima da Serra. In five collecting expeditions, 42 species were found at the study site, distributed on eight genera. A list of the species, analytical keys for genera and species, as well as scanning photomicrographs of the achenes are presented.

Leaf appearance rate and phyllochron are related variables which play a central role in forage production. Phyllochron is the time interval between the appearance of successive leaves and varies according to a number of environmental factors, among which temperature is the most important. The experiment was conducted in natural pasture with the aim of testing phyllochron variation under different seasons, herbage allowances, and topographic positions. Marked tillers were used to define the phyllochron, establishing a relationship between the number of leaves produced against thermal time during the sampling period. The time (expressed in °C) needed for the emergence of a leaf is equal to 1/b, where b is the slope coefficient of the regression. The lines for the season combinations, herbage allowances and topographic positions sampled were compared. Under Spring and Summer conditions, the phyllochrons for P. notatum and C. selloana were 156°C and 238°C respectively, regardless of treatment.A taxa de aparecimento de folhas (TAF) e o filocrono são conceitos associados, que exercem forte influência na produção de forragem. O filocrono é o intervalo de tempo entre o aparecimento de duas folhas sucessivas acima do pseudocaule e varia de acordo com alguns fatores ambientais, sendo a temperatura o fator determinante. O experimento foi conduzido em pastagem natural em Eldorado do Sul, RS, com o objetivo de testar a variação no filocrono em diferentes estações do ano, níveis de oferta de forragem (NOF) e posições topográficas (PT). Para a definição do filocrono, foram amostrados perfilhos marcados e estabeleceu-se a relação entre número de folhas produzidas e a soma térmica do período amostral. A soma térmica (em °C) necessária para que a planta emita uma folha é igual a 1/b, sendo b o coeficiente angular verificado na regressão. As retas obtidas para as combinações entre estações, NOF e PT foram comparadas. Em condições de primavera e verão, se obteve filocrono de 156°C para P. notatum e de 238°C para C. selloana, independentemente dos tratamentos avaliados.

O presente estudo objetivou avaliar modificações ocorridas na vegetação em uma área de campo natural, após oito anos sem influência de pastoreio. A área situa-se na Estação Experimental Agronômica da UFRGS, no município de Eldorado do Sul, RS, onde foram realizadas amostragens em 1984 e 1992. Dezesseis unidades amostrais permanentes de 0,25 m² foram utilizadas para verificar a presença e o valor de cobertura das espécies, pela escala de Daubenmire. São apresentados os valores de freqüência e cobertura absolutas (FA e CA, respectivamente) das espécies de Gramineae, Compositae, Rubiaceae, Leguminosae, Umbelliferae e Cyperaceae nos levantamentos de 1984 e 1992. O trabalho evidenciou a relação entre a forma biológica das espécies predominantes e os estados pastejado ou excluído. Em Gramineae, espécies rasteiras, estoloníferas ou rizomatosas (Paspalum notatum, Axonopus affinis e outras), características da área pastejada, foram substituídas por plantas de hábito cespitoso (Andropogon lateralis, Elyonurus candidus e outras), capazes de sombrear e sobrepujar as de baixo porte. Espécies de compostas e rubiáceas, de um modo geral, apresentaram uma redução em FA e pouca alteração em CA. As leguminosas apresentaram principalmente um aumento em FA, mantendo a CA praticamente constante. As umbelíferas destacaram-se pelo aumento da CA em metade de suas espécies. Ocorreu o surgimento de 25 e o desaparecimento de 42 espécies em 1992.The aim of this study was to evaluate modifications after eight years without grazing in a native grassland area, located at the Estação Experimental Agronômica - UFRGS, in Eldorado do Sul, RS. Vegetation surveys were done in 1984 and 1992. Sixteen permanent sample quadrats (0.25 m²) were established and presence of species and cover-abundance values according to the Daubenmire scale were recorded. Absolute frequencies and cover values (AF and AC, respectively) in 1984 and 1992 are presented for Gramineae, Compositae, Rubiaceae, Leguminosae, Umbelliferae and Cyperaceae species. The study showed the relation between the growth forms of the most abundant species and the grazed and ungrazed situations. Creeping, stoloniferous and rhizomatous species of Gramineae (Paspalum notatum, Axonopus affinis and others) were conspicuous when the area was under grazing, being replaced by tussock-type plants (Andropogon lateralis, Elyonurus candidus and others) able to dominate and shade out small understory herbs, when excluded. Compositae and Rubiaceae species showed a reduction in AF and few changes in AC. Leguminosae species had an increase in AF, presenting almost constant values for AC. Half of the Umbelliferae species presented an increase in AC in the second survey. Twenty five species appeared and 42 vanished in 1992.

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora.