RESUMO:Achyrocline satureioides (marcela) é utilizada na medicina popular brasileira, na forma de chá, como tratamento de patologias digestivas e infl amatórias. O efeito anti-proliferativo de infusões de marcela sobre o ciclo celular da cebola foi avaliado, utilizando-se infl orescências de marcela recém coletadas (2005) e após armazenamento por 30 meses (2003). Preparou-se as infusões em duas concentrações: 5,0 mg/mL (concentração usual como chá) e 20 mg/mL. Utilizaram-se 3 grupos de 6 bulbos de cebola para cada população de marcela. Retirou-se um grupo de bulbos controle de cada população. Todos os bulbos enraizados em água destilada foram transferidos para os extratos de marcela e permaneceram por 24 horas, (os bulbos controle permaneceram em água). As radículas foram coletadas, fi xadas em etanol-ácido acético (3:1) por 24 h e estocadas em álcool 70%. Foram analisadas 6000 células por grupo de bulbos, e os índices mitóticos calculados submetidos a análise estatística pelo teste 2 a 5%. Conclui-se que as infusões de marcela possuem ação antiproliferativa sobre o ciclo celular da cebola e que essa ação inibitória da divisão celular aumenta conforme aumento da concentração, bem como após o armazenamento.Unitermos: Achyrocline satureioides, Allium cepa, Asteraceae, Liliaceae, atividade antiproliferativa, índice mitótico, planta medicinal.ABSTRACT: "Anti-proliferative effect of infusions of Achyrocline satureioides on the Allium cepa cell cycle". Achyrocline saturoides (marcela) is used in Brazilian folk medicine as a tea in the treatment of digestive and infl ammatory diseases. The anti-proliferative effect of infusions of marcela on onion cell cycle was evaluated by using the infl orescences of recently collected marcela and after the storage for 30 months. Marcela infl orescences were collected for the infusion preparations in 2003 and in 2005 (used still fresh). We prepared the infusions at two concentrations 5.0 mg/mL (concentration used as tea) and 20 mg/mL. We used two groups of six onion bulbs for each population of marcela, and one group of bulbs of each population was withdrawn as a control group. All bulbs rooted in distilled water and after they were transferred to the extracts of marcela and they were kept there for 24 hours (control bulbs remained under water). The root tips were collected, after fi xed in ethanol acetic acid (3:1) for 24 hours and, stored under alcohol 70%. A total of 6000 cells per group of bulbs was analyzed, and the mitotic indexes were calculated and undergone to statistical analysis by using 2 at 5%. The conclusions were that the infusions of marcela have anti-proliferative action on the cell cycle of onion and that this inhibitory action on the cell division increases according to the increase of the infusion concentration, after storage as well.

RESUMO(Composição florística de trepadeiras ocorrentes em bordas de fragmentos de floresta estacional, Santa Maria, Rio Grande do Sul, Brasil) Foi realizado o levantamento das espécies de trepadeiras ocorrentes em bordas de fragmentos de floresta estacional em Santa Maria, RS. As coletas foram quinzenais, durante o período de março de 2006 a março de 2007, e se restringiram às margens dos fragmentos florestais que se estendem ao longo das principais rodovias de acesso ao município. Com base no modo de ascensão, hábito e ocorrência, as espécies foram classificadas respectivamente em: trepadeiras volúveis, com gavinhas ou apoiantes; herbáceas ou lenhosas; raras, ocasionais ou abundantes. Foram registradas 73 espécies, distribuídas em 47 gêneros e 24 famílias. Apocynaceae (nove espécies), Sapindaceae (oito), Bignoniaceae (sete), Convolvulaceae (sete) e Passifloraceae (seis) foram as famílias de maior riqueza específica. Constatou-se o predomínio de trepadeiras volúveis, seguido pelas formas dotadas de gavinhas e das apoiantes. O hábito herbáceo prevaleceu sobre o lenhoso e, quanto à ocorrência, a maioria das espécies foi abundante, seguida pelas ocasionais e raras. Palavras-chave: fragmentos florestais, plantas trepadoras, lianas. ABSTRACT(Floristic composition of climbers along the edges of seasonal forest fragments, Santa Maria, Rio Grande do Sul, Brazil) A survey of climbing species growing along the edge of seasonal forest fragments in Santa Maria, RS, was carried out. Collections were made between March 2006 and March 2007, only at the edge of forest fragments found along main access roads. Based on climbing pattern, habit, and occurrence, the species were classified into: twiners, plants with tendrils or scandent; herbaceous or woody; rare, occasional or abundant. Seventy three species were registered, distributed in 47 genera, and 24 families. Apocynaceae (nine species), Sapindaceae (eight), Bignoniaceae (seven), Convolvulaceae (seven) and Passifloraceae (six) were the families with the highest species richness. Twiners were dominant, followed by forms with tendrils, and scandent forms. Herbaceous habit was predominant over woody and, regarding to the occurrence, most species were considered abundant, followed by occasional and rare.

Abstract:Root climbers constitute a distinctive group within climbing plants and some evidence suggests that they are associated with high precipitation and low light availability at local scales, which is in contrast with general patterns of liana distribution in the tropics. The influence of precipitation and seasonality on the occurrence of root climbers was evaluated both globally and in the tropics. The presence/absence of root climbers was recorded in 174 sites of Alwyn H. Gentry Forest Transect Data Set. The effects of mean annual precipitation and dry-season length (and temperature) on their occurrence were analysed using logistic regressions. Root climbers were significantly more frequent in sites with greater precipitation and reduced seasonality. Increasing temperature reduced root-climber occurrence in tropical sites, but this effect was marginally significant at a global scale. Dry and open habitats appear unsuitable for root climbers. This can be explained by the susceptibility to desiccation of adventitious roots and/or the low acclimation ability of these climbers to high irradiance.

Most of southern Brazil is located in a subtropical region, thus representing a climatic and biogeographic transition, which results in different floristic contingents of both tropical and temperate origin in any particular study area. In order to verify the biogeographic affinities of climbing plants, a floristic survey was carried out in a Semideciduous Seasonal Forest remnant located in mideastern Rio Grande do Sul. The presence of the sampled species was recorded for three gradually more distant areas along four divergent expansion lines starting from the study area: northeast, northwest, midwest, and southwest. The distribution data were compiled from the available local and regional literature. The 82 species found comprised 55 genera and 33 families; most species occurred in a single family (Asteraceae), followed secondarily by Apocynaceae, Passifloraceae, Bignoniaceae and Fabaceae. Many species presented a relatively large geographic range, and most species occurred along the northern tropical expansion line. Multivariate analysis included the study area in a group formed exclusively by rain forests of a northeastern expansion line, indicating a southern continuity of the Brazilian Atlantic Forest, although it was locally represented by a lower number of species.

Questions How do climbing species richness and composition change between subtropical and temperate areas of southern South America? How do growth form (lianas and vines) and climbing mechanisms change between subtropical and temperate areas of southern South America? How much of the diversity of species and traits of the extratropical climbing flora is derived from taxa shared with the tropical region? Location Subtropical (23–30° S) and temperate (>30° S) areas of South America. Methods An extensive literature search was carried out in the main databases concerning the flora of southern South America. Climbing species occurrence in subtropical and temperate areas and climbing traits were retrieved. Differences in the frequencies of both growth forms and climbing mechanisms between areas were evaluated using chi‐square analyses. Trait frequencies in subtropical and temperate floras were analysed with and without considering species shared with the tropical region. Results Climbing species richness decreased from subtropical to temperate areas, and there were changes in the taxonomic composition. The frequency of growth forms and climbing mechanisms differed between subtropical and temperate areas. Herbaceous vines accounted for 85% of temperate‐exclusive species. Twiners contributed less to climber richness in the temperate area, while tendril‐bearers and leaf‐climbers became more important; root‐climbers were only found in temperate forests. Species shared with the tropical region increase the number of liana species in both subtropical and temperate floras, but alter the frequencies of climbing mechanisms in the subtropical flora only. Conclusions Results call for a re‐evaluation of the importance that is given to climbers in regions outside the tropics. Vines must be included in models of distribution and abundance of climbers in order to gain a better understanding of climbing plant ecology. The association between climbing mechanisms and the success of climbing plant species in different ecosystems must be further investigated.