Silvia Teresinha Sfoggia Miotto

O gênero Senna (Leguminosae, Caesalpinioideae) no Rio Grande do Sul, Brasil

This paper presents a taxonomic study of the species of the genus Senna occurring in Rio Grande do Sul State, Southern Brazil. Nineteen species were found and the occurences of Senna aphylla (Cav.) H.S. Irwin & Barneby, S. araucarietorum H.S. Irwin & Barneby, S. pendula (Willd.) H.S. Irwin & Barneby, S. scabriuscula (Vogel) H.S. Irwin & Barneby and S. spectabilis (DC.) H.S. Irwin & Barneby are recorded for the first time in Rio Grande do Sul. Analitical key, species descriptions and illustrations are presented. Additional informations are provided concerning geographic distribution, habitats, common names and economic uses.

Números cromossômicos e implicações sistemáticas em espécies da subfamília Caesalpinioideae (Leguminosae) ocorrentes na região sul do Brasil

The subfamily Ceasalpinioideae (Leguminosae) comprises around 2,800 species, many of which occurring in Brazil. For the Southern region of Brazil, 56 species economically, socially and scientifically important, are cited, distributed along different environments, but detailed taxonomic and cytogenetic studies are still missing. This paper reports chromosome number analysis in 74 accessions of 27 taxa belonging to ten genera of tribes Cassieae, Caesalpinieae, and Cercideae. The determined chromosome numbers were 2n = 32, 28, 26, 24, 22, 16 and 14. For seven species the chromosome numbers were determined for the first time: Cassia leptophylla, Senna araucarietorum, S. hilariana, S. neglecta, S. oblongifolia, Chamaecrista repens and Pomaria stipularis. Most species had 2n = 28 chromosomes, 2n = 26, 24, and 22 being also found. The genus Chamaecrista differs from the others studied as all its taxa presented 2n = 32, 16, and 14, the first one derived by polyploidy. The basic number of x = 14 was proposed for the species of nine of the studied genera, while x = 13, 12 and 11 would have probably been originated by disploidy. For the genus Chamaecrista, x = 8 is suggested for most species and x = 7 for the species of section Xerocalyx. Polyploidy seems to have played an important role in the initial diversification of the group, accompanied by several disploid reductions during the evolutionary process. The number of chromosomes distinguishes Chamaecrista from the other genera. This, together with other analyzed characteristics, as well as literature data, supports the separation of this genus from the other Cassieae genera.

Micromorfologia da superfície do fruto de espécies de Mikania Willd. (Asteraceae) ocorrentes no estado do Rio Grande do Sul, Brasil

This work presents the surface micromorphology of fruits of 15 taxa of Mikania Willd. studied under scanning electron microscopy (SEM). The aim was to find characters to separate close species that occur in Rio Grande do Sul State. Such characters had taxonomic value for some of them. The species were separated into four groups according to the pattern. The pattern with striated periclinal and anticlinal walls with verrucose projections was the most constant in the species of Mikania Willd. analyzed.

Aspectos florísticos e ecológicos da vegetação campestre do Morro da Polícia, Porto Alegre, RS, Brasil

Estudou-se a variacao da composicao floristica da vegetacao campestre e suas relacoes com altitude e exposicao no Morro da Policia, de origem granitica, em Porto Alegre, Rio Grande do Sul, a 30oS e 51 oW. O levantamento foi realizado de novembro de 1992 a novembro de 1994. A presenca e frequencia de especies foi avaliada usando o metodo de pontos sobre transeccoes em 19 unidades de vegetacao, as quais foram delimitadas com base na exposicao da encosta (N, S, L, O) e altitude (160 a 280m). Os dados foram submetidos a analise multivariada de agrupamentos e ordenacao. Nas transeccoes foram observadas 189 especies, sendo Poaceae, Asteraceae e Apiaceae as familias mais frequentes e Trachypogon montufari e Schizachyrium tenerum as especies dominantes. A analise de agrupamentos e de ordenacao revelou conexoes entre variacao da vegetacao e fatores altitude e exposicao solar. Aristida laevis e Sorghastrum albescens sao caracteristicas de comunidades mais expostas a radiacao solar, enquanto Agenium villosum e Eryngium eriophorum o sao de comunidades menos expostas. Vernonia nudiflora e Axonopus suffultus caracterizam as areas mais elevadas do morro, enquanto Eupatoriitm ligulifolium e Sorghastrum albescens as mais baixas.

O gênero Merremia (Convolvulaceae) na Região Sul do Brasil

Resumo Merremia Dennst. ex Endl. compreende aproximadamente 60 especies, amplamente distribuidas nos tropicos e subtropicos de ambos os hemisferios. Das 14 especies do genero conhecidas para o Brasil, nove foram confirmadas para a Regiao Sul: M. cissoides (Lam.) Hallier f., M. digitata (Spreng.) Hallier f. var. digitata , M. digitata var. elongata (Choisy) D.F.Austin & Staples, M. dissecta (Jacq.) Hallier f., M. hassleriana (Chodat) Hassl., M. macrocalyx (Ruiz & Pav.) O’Donell, M. tomentosa (Choisy) Hallier f., M. tuberosa (L.) Rendle e M. umbellata (L.) Hallier f. Sao fornecidos chave de identificacao, descricoes morfologicas, dados de distribuicao geografica, habitat e ilustracoes dos taxons. Merremia hassleriana constitui uma nova ocorrencia para o Parana. The genus Merremia (Convolvulaceae) in Southern Brazil Abstract Merremia Dennst. ex Endl. comprises about 60 species widely distributed in the tropics and subtropics of both hemispheres. Among the 14 species occurring in Brazil, nine were confirmed for the Southern region: M. cissoides (Lam.) Hallier f., M. digitata (Spreng.) Hallier f. var. digitata , M. digitata var. elongata (Choisy) D.F.Austin & Staples, M. dissecta (Jacq.) Hallier f., M. hassleriana (Chodat) Hassl., M. macrocalyx (Ruiz & Pav.) O’Donell, M. tomentosa (Choisy) Hallier f., M. tuberosa (L.) Rendle, and M. umbellata (L.) Hallier f. Analytical key, morphologic descriptions, geographical data, habitat and illustrations of the taxa of Merremia in Southern Brazil are provided. Merremia hassleriana is a new record for Parana State.

Cytogenetics and Cytotaxonomy of Brazilian Species of Senna Mill. (Cassieae - Caesalpinioideae - Leguminosae)

Abstract Chromosome numbers, meiotic behaviour, meiotic indexes and pollen fertility are reported for 17 Senna Mill. species occurring in Southern Brazil. Haploid numbers were n=11, 12, 13, 14 and 28. No intraspecific variability was detected; n=14 predominated. The only accession of S. rugosa showed to be tetraploid, in contrast to the a previous reference for this species. Meiotic behaviour was generally regular for all species and accessions, but some irregularities such as uni and multivalents and unequal segregation were occasionally observed. Meiotic indexes were high, over 95%. Mean pollen fertility was over 81% for all species, but in some taxa much lower values were found in some accessions. All species had prolate-spheroidal pollen grains. No relation between grain size, taxonomic position and chromosome number could be established. Our results, together with literature data, suggest that x=14 is the basic number for the genus, probably a secondary number derived from the x=7 suggested for all Caesalpinioideae, and that the other numbers in the genus represent a disploid series. A broader cytogenetic survey of a more representative number of species, along the geographic distribution of the genus, should be done addressing questions such as the extent of intra and inter-specific variability in chromosome number, occurrence of polyploidy and the real role of disploidy in Senna evolution

Número cromossômico em espécies brasileiras de Adesmia DC. (Leguminosae-Faboideae)

Chromosome numbers of 11 South-Brazilian species of Adesmia were determined. The cytological preparations were obtained by squashing cells of root tips, using the acetic-orcein method. The chromosome number for all the species studied was 2n=20, excepting A. incana var. incana with 2n=ca.40. The counts are new for nine species, and the other two agree with the literature. It is suggested x=10 as the basic number for the genus. Up to the present only four species were cited as polyploid.

O gênero Polygala L. (Polygalaceae) na região Sul do Brasil

In Southern Brazil, the Polygalaceae family is represented by five genera: Acanthocladus, Bredemeyera, Monnina, Polygala, and Securidaca. The genus Polygala is the largest of the Polygalaceae family, with approximately 725 species widely distributed in the world, in all types of environment. Approximately 140 taxa of Polygala are known in the Brazilian flora. The survey recorded 39 species of Polygala to Southern Brazil, representing the subgenera Hebeclada, Ligustrina and Polygala, the last one with 31 species. Full descriptions, illustrations, analytical keys, data on habitat, geographic distribution, and ecological observations are provided.

Combining ecological and morphometrical approaches to increase the resolution within the Galactia neesii (Leguminosae) complex

The objective of this paper is to resolve the taxonomic complex formed by G. neesii, G. martii, their infraspecific taxa, and other similar species, totaling eight names. This group grows from southern Uruguay to northeastern Brazil, and the morphology of individuals gradually changes along this latitudinal gradient, making it possible to identify many morphotypes that have been assigned by previous authors either as species or varieties. We combined ecological and morphometrical approaches to increase the resolution within this complex. We used two techniques of cluster analysis within the ecological data to find the correct number of clusters in the data set. The significant groups found by cluster analysis were then tested a posteriori with a permuted MANOVA to discover congruent morphological groups. Our results showed that from the eight previously hypothesized groups, only two were both ecologically and morphologically significant and could represent separately evolving lineages. The necessary nomenclatural changes as well as a short taxonomic description of the taxa are provided in this paper.

Characterizing Polygala L. (Polygalaceae) Species in Southern Brazil Using ISSR

The genus Polygala is one of the seven Polygalaceae genera that occur in the Brazilian flora, covering approximately 110 species. During the taxonomic review of Polygalaceae in Southern Brazil, difficulties were found when classifying species with very similar morphology, and morphological data alone could not clarify these interspecific relationships. In this context, inter-simple sequence repeat (ISSR) molecular markers were used in an attempt to characterize the genetic diversity and relationships among Polygala species. Nine Polygala species were analyzed using six selected ISSR primers that generated a total of 75 bands (100% polymorphic). The relationships were evaluated by dendrograms using the unweighted pair group method using arithmetic averages algorithm. The use of ISSR to solve the taxonomic problems was very useful for the Brazilian Polygala species. This is the first report of a molecular characterization of the Brazilian Polygala species to successfully group the different species. The ISSR results are in agreement with the morphological evidence of a new Polygala species from Southern Brazil.