As Clusiaceae Lindl. (Guttiferae Juss) s.s., Calophyllaceae J. Agardh e Hypericaceae Juss. no Parque Nacional do Viruá (Roraima) e biologia reprodutiva de Clusia s.p. (Clusia nitida Bittrich, ined)

Abstract

The Viruá National Park (PNV) is expected to possess a high biodiversity. It contains a mosaic of vegetation types and various taxonomic and ecological studies are exploring the previously almost unknown flora. This study is a floristic survey of the species of the families Clusiaceae s.s., Calophyllaceae and Hypericaceae in the PNV and an investigation of the floral biology and visitors and potential pollinators of Clusia nitida Bittrich, ined. (Clusiaceae s.s.). The field work was conducted between November 2009 and January 2011. Collections of fertile individuals were made in different vegetation types and collections of Clusia nitida were made so that we could establish the flowering phenology and make visual observations and experiments to determine the breeding system and floral visitors of C. nitida.In the PNV, "Clusiaceae s.l." is represented by 7 genera and 17 species: Calophyllum (1), Caraipa (2), Clusia (6), Platonia (1), Symphonia (1), Tovomita (2) and Vismia (4), occurring in all environments of the park. Six new records are made for Roraima and there is the possibility of a new species of Vismia, which requires more complete fertile material before confirmation. We present identification keys, taxonomic descriptions, photographic illustrations and document the occurrence of species in the PNV and elsewhere, thus contributing to the information about the family in Amazonia. The flowering season of the species is from September to February and the fruit formation is from November to July. The sex ratio between staminate and pistillate and staminate individuals is 2:1, respectively. The anthesis and floral resin secretion occur first in the staminate flowers and coincides with the beginning of the activities of the floral visitors. Clusia nitida is a non-apomictic species. The reproductive success was greater in the hand-pollination treatment, showing the importance of a vector to carry the pollen from the staminate to the pistillate flower. Clusia nitida was visited by eight species of bees and the main pollinators were Trigona spp. Taxonomic studies like this and studies of floral biology are very important so that we can reduce the scarcity of basic, reliable data in the Amazon.