ABSTRACT Oncidiinae is an exclusively Neotropical orchid subtribe with about 1600 described species and an impressive array of vegetative and floral morphological adaptations. We present the results of a literature survey on the pollination strategies and breeding systems of this orchid subtribe. The flowers are pollinated by a wide range of insects (mostly bees) and, sometimes, hummingbirds. Several genera reward their pollinators with floral resources such as oils, nectar or perfumes. Whereas pollination by oil-gathering bees likely evolved several times within Oncidiinae, exclusive pollination by perfume-gathering male Euglossine bees is likely restricted to a set of closely-related genera. Pollination by food or sexual deception is also present within the subtribe. Up to date, the pollen-vectors of the 92 species of Oncidiinae studied so far are as follows: 84.7 % are pollinated by bees, 6.5 % by wasps, 4.3 % by hummingbirds, 3.2 % by butterflies and 3.2 % by flies. Oncidiinae orchids are preferentially self-incompatible (69.4 % of the species studied so far), some may also present protandry as a mechanism to promote cross-pollination. Fruiting success is generally low. The rate of visitation with subsequent pollination is low, in general, which contributes to the low reproductive success of this plant group.

Lyroglossa e Pteroglossa(Orchidaceae: Spiranthinae) são registradas pela primeira vez para o Rio Grande do Sul. Descrições, ilustrações, notas taxonômicas e distribuição são apresentadas. Nós também fornecemos uma chave artificial para distinguir os gêneros do “Clado Stenorrhynchos” registrados até o momento para o Rio Grande do Sul.

Lyroglossa and Pteroglossa(Orchidaceae: Spiranthinae) are first recorded for Rio Grande do Sul. Descriptions, illustrations, taxonomic notes and distribution are presented. We also provide an artificial key to distinguish the genera of the “Stenorrhynchos Clade” reported so far in Rio Grande do Sul.

Gunnera perpensa (Gunneraceae) é uma planta de origem africana extensamente utilizada na medicina tradicional do país. Esta espécie é conhecida por suas atividades no sistema reprodutor feminino, como indução ou aumento do trabalho de parto, tratamento da infertilidade em mulheres, expulsão da placenta e/ou impedimento de hemorragia pós-parto. Tais atividades devem-se, provavelmente, ao sinergismo existente entre o (z)-venusol, composto majoritário, e outros compostos presentes na planta. No sul do Brasil, encontra-se uma espécie nativa, Gunnera manicata L., pertencente à família Gunneraceae. Apesar do uso tradicional de G. perpensa, não há informações farmacológicas e fitoquímicas a respeito da espécie sul Americana de Gunnera. Assim, o objetivo deste estudo foi investigar a atividade de extratos aquosos da espécie brasileira G. manicata no sistema reprodutor de ratas Wistar imaturas através de ensaio uterotrófico e verificar a presença do composto (z)-venusol utilizando-se cromatografia líquida acoplada a espectrômetro de massas em tandem (CL-EM/EM). Para a análise estatística, utilizou-se ANOVA/Bonferroni (p<0,01). Os resultados obtidos demonstraram que os extratos de G. manicata testados não apresentaram atividade anti ou estrogênica in vivo. Na análise química não foi verificada a presença do composto (z)-venusol. Este estudo representa o primeiro screening realizado com a espécie sul-americana G. manicata.

Gunnera perpensa (Gunneraceae) is an African plant widely used in traditional medicine. This species is known for its activity involving the female reproductive system, such as inducing or increasing labor, treating female infertility, expelling the placenta and/or preventing post-partum hemorrhage. These properties are probably due to (z)-venusol, a majoritary compound, and its action in conjunction with substances in the whole extract and other natural products. In southern Brazil, a native species Gunnera manicata L. that also belongs to Gunneraceae can be found. In spite of the traditional use of G. perpensa, there is no pharmacological and phytochemical information regarding the South American Gunnera species. Therefore, the aim of this study was to investigate the activity of Brazilian G. manicata aqueous extracts on the reproductive system of immature female Wistar rats through a uterotrophic assay and to verify the presence of (z)-venusol by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Data were analyzed by analysis of variance (ANOVA) and Bonferroni´s post-hoc test (p< 0.01). Results obtained shown that G. manicata extracts did not present in vivo anti or estrogenic activity. Furthermore, (z)-venusol compound was not found. This study represents the first preliminary screening done on the South American G. manicata species.

El segundo libro de Darwin fue íntegramente dedicado a la morfología floral y polinización de diversos grupos de orquídeas de regiones templadas y tropicales. Este libro fue publicado en 1862 y parece haber sido concebido como una fuente de pruebas o un complemento para ideas sugeridas en El origen de las especies, en especial la noción sobre las ventajas del cruzamiento entre individuos diferentes, aunque sean hermafroditas (como es el caso de las orquídeas). La gran diversidad de morfologías florales y las diversas estrategias reproductivas que promueven la polinización cruzada en Orchidaceae fascinaron a Darwin, quien utilizó a este grupo de plantas como modelo para apoyar sus ideas. Darwin describió por primera vez y de modo impecable estrategias reproductivas como la protandria en orquídeas terrestres y la producción de flores imperfectas (unisexuales) en Catasetum, entre muchas otras contribuciones. Se analizan las ideas y propuestas de Darwin en este libro a la luz de nuestros conocimientos actuales y se muestran en gran parte correctas y vigentes.

Darwin s second book was totally dedicated to the floral functional morphology and pollination of temperate and tropical orchids. This book was published in 1862 and was likely conceived as an assemblage of evidence supporting ideas that were proposed in -On The Origin of The Species-; namely, the advantages of the intercrossing between different coespecific individuals, even if they are hermaphrodite (like the orchids). The great floral diversity and the outstanding number of reproductive strategies that promote cross-pollination in Orchidaceae fascinated Darwin who, in turn, used this plant group as a model to support his ideas. Darwin described for the first time and in a very accurate way, orchid reproductive strategies that clearly promote cross-pollination, such as protandry in terrestrial orchids and the production of unisexual flowers in Catasetum, among many other important contributions. Darwin s ideas and proposals regarding Orchidaceae are analyzed on the light of our present knowledge and prove to be mostly correct and valid.

Amostras de Ephedra tweediana Fisch & C.A. Meyer, coletadas de populações nativas da Reserva Biológica do Lami José Lutzenberger (Porto Alegre, RS, Brasil), e amostras de Ephedra triandra Tul., obtidas de plantas cultivadas em Porto Alegre/RS, foram extraídas com acetona, derivatizadas com ciclohexanona e analisadas por CG/EM. Para verificação da eficiência da metodologia, além das amostras de Ephedra tweediana e E. triandra, foram analisadas cinco amostras comerciais de Ephedra, de procedências distintas, cedidas por farmácias de manipulação locais. Os resultados encontrados indicam a ausência de efedrinas em Ephedra tweediana e E. triandra e presença de efedrina e/ou pseudoefedrina nas amostras comerciais.

Samples of Ephedra tweediana, collected from native populations occurring in the Reserva Biológica do Lami José Lutzenberger (Porto Alegre, RS, Brazil), and from cultivated plants of Ephedra triandra were submitted to extraction with acetone, derivatized with cyclohexanone and analyzed by GC/MS. In order to verify the efficiency of the methodology, besides Ephedra tweediana and E. triandra, samples of five commercial Ephedra extracts were analyzed, from distinct origins, get up from local drugstores. The results showed the absence of ephedrines in Ephedra tweediana and E. triandra, and the presence of ephedrine and/or pseudoephedrine in commercial samples.