No abstract

-(Floristic composition of aquatic and palustris plants in the Guarapiranga Reservoir, São Paulo, Brazil). The aim of this study was to investigate the composition of aquatic and palustris plants in the Guarapiranga reservoir, and to contribute to the taxonomic knowledge of the species. Monthly fieldworks were performed from June/2008 to May/2009, in 20 stands of aquatic plants distributed throughout the reservoir. The species present were collected and registered in each stand. The aquatic macrophytes community of the reservoir is composed of 133 species belonging to 89 genera distributed in 45 families being 127 angiosperms, five ferns and one liverwort. The most representative families were Cyperaceae with 27 species, followed by Poaceae (14) and Asteraceae (10). Of the 67 species considered as weeds, only 14 are subspontaneous or naturalized, the other 120 species are native, six of which are endemic in Brazil. The present work contributed significantly to the flora of aquatic plants and palustris of São Paulo, as well as to List of Flora of Brazil, registering species that had not been previously recorded to the state of São Paulo, in this the work is besides a key of identification and descriptions of the species present in the study area. In conclusion, species richness of aquatic plants and palustris at Guarapiranga is high. Key words: Aquatic plants, macrophytes, wetlands, hydrophytes.Resumo -(Levantamento florístico de plantas aquáticas e palustres na Represa Guarapiranga, São Paulo, Brasil) -O objetivo desse trabalho foi verificar a composição de plantas aquáticas e palustres no reservatório Guarapiranga, além de contribuir para o conhecimento taxonômico das espécies. Foram realizadas coletas mensais de julho/2008 a junho/2009, em 20 bancos de plantas aquáticas distribuídos ao longo de todo o reservatório. Em cada banco foram coletadas e registradas as espécies presentes. A comunidade de plantas aquáticas e palustres do reservatório é composta por 133 espécies, pertencentes a 89 gêneros, distribuídos em 45 famílias, sendo 127 de Angiospermas, 5 de Samambaias e 1 de Hepática. As famílias mais representativas foram Cyperaceae com 27 espécies, seguida de Poaceae (14) e Asteraceae (10). Das 67 espécies consideradas plantas daninhas ou infestantes, apenas 14 são subespontâneas ou naturalizadas, as demais 120 espécies são nativas, sendo 6 endêmicas do Brasil. O presente trabalho contribuiu significativamente para a Flora de plantas aquáticas e palustres, bem como para Lista da Flora do Brasil, registrando espécies que não haviam sido referidas anteriormente para o estado de São Paulo, além da apresentação de uma chave de identificação e descrições para as espécies presentes na área de estudo. Foi possível concluir que a Represa Guarapiranga possui uma elevada riqueza de plantas aquáticas e palustres Palavras-chave: plantas aquáticas, macrófitas, alagados, hidrófitas.

The coastal region of the São Paulo state (Southeastern Brazil) is marked by the presence of the Serra do Mar, a system of mountain ranges with altitude up to 1,000 m. Due to the difference of proximity of the mountain range to the coastline, the coastal plains have different width. As a consequence, the rivers that cross the plains also have different length, greater or less influence of marine waters and slope variation. We carried on an inventory of aquatic macrophyte species in order to assess the species and life form richness and latitudinal distribution in this region. Macrophytes were inventoried at 100 sampling sites in eight rivers (between 9 and 19 sites per river) in March 2017. General descriptions on taxonomic aspects, life forms and frequency of occurrence of the macrophytes were explored. We recorded 45 taxa of aquatic macrophytes belonging to 24 families. Three species are exotic, but they presented low frequencies of occurrence. The vast majority of the taxa have emergent life form. Floating and submerged macrophytes were found in only two rivers. The most frequent species were Crinum americanum L. (Asparagales, Amaryllidaceae), Spartina alterniflora Loisel. (Poales, Poaceae) and Schoenoplectus californicus (C. A. Mey.) Soják (Poales, Cyperaceae). Most taxa are rare in terms of occurrence. Only four species occurred along a large part of the north-south stretch sampled and these, possibly, have a wide tolerance to the variation in resource requirements and salinity. The north-south gradient of the taxa occurrence may be related to the diversity of environmental characteristics due to differences in the rivers length and coastal plains width.