Foram analisadas 17 espécies subordinadas a oito gêneros ocorrentes nas restingas do Estado do Rio de Janeiro, com o objetivo de contribuir para a caracterização polínica dessas espécies e para o catálogo polínico das restingas do Rio de Janeiro. Os grãos de pólen foram acetolisados, analisados e fotomicrografados sob microscopia de luz. Para observar detalhes da superfície, grãos de pólen não acetolisados foram analisados em MEV. Apenas Byrsonima sericea possui grãos de pólen isopolares, pequenos e tricolporados. Nas demais espécies os grãos de pólen foram apolares e apresentaram atributos que foram utilizados na chave polínica sendo as principais caraterísticas utilizadas, o tamanho dos grãos de pólen, a quantidade e dimensões dos poros, a ornamentação da sexina e dos colpóides. Conclui-se que as espécies são palinologicamente distintas e as características polínicas mostraram ser um bom recurso disponível aos pesquisadores que poderão utilizar na taxonomia e demais áreas afins.

Nesting and use of pollen resources by Tetrapedia diversipes Klug (Apidae) in Atlantic Forest areas (Rio de Janeiro, Brazil) in different stages of regeneration. The nesting in trap-nests and use of pollen sources in larval food by Tetrapedia diversipes Klug, 1810 (Apidae) was compared between regenerating areas of Atlantic Forest. The study was conducted between April 2008 and October 2009 at União Biological Reserve, Rio de Janeiro, Brazil. T. diversipes nested in 66 trap-nests and showed a peak of nesting during the months of highest rainfall. The most frequent pollen type in brood cells during the wet season was Dalechampia sp. 1. During the dry season, the type Ludwigia sp. was the most frequent, followed by Dalechampia sp. 2. The high frequency of Dalechampia and Ludwigia species in the larval food, observed in both habitats and in the two seasons could be considered relevant for T. diversipes, suggesting highly selective diet based primarily on two plant species unrelated, but similar in size of pollen grains.

Hummingbirds are the most important group of pollinating birds in the Neotropics and tend to use, concomitantly, more than one plant species as food source. Pollen may be mixed on hummingbirds' body due to the visits to different plant species; therefore, these birds may promote heterospecific pollen deposition (HPD). The hummingbirds potential to promote HPD, the occurrence of HPD and its implications in plant reproduction are scarcely known in the Atlantic Forest. We have studied the transport of pollen by three hummingbird species from the Brazilian Atlantic Forest. We have also checked the actual HPD occurrence under natural conditions in two plant species, namely Canistropsis seidelii and Psychotria nuda. Moreover, we investigated Nidularium innocentii reproductive system evaluating the effect of HPD on its reproduction by simulating a pollen mixture pollination. We found hummingbirds transporting heterospecific pollen mixtures on their bodies, which in turn were deposited onto stigmas of different species. We have also found that mixed pollen deposition had negative effect on the fitness of N. innocentii. We conclude that hummingbirds carry pollen mixtures at the same body parts, leading to potential HPD at the community level. Moreover, hummingbird-plant communities in the Atlantic Rainforest show remarkable similarities in temporal organization and interaction pattern. This suggests that HPD may be a widespread phenomena in these communities.

Pollen grains from twelve species of the Passifloraceae family from the Brazilian Atlantic Forest were analyzed: Passiflora subg. Astrophea (1sp.), P.subg. Decaloba (1sp.) and P.subg. Passiflora (10spp.). The current study aims to acquire additional information and feature the pollen morphology of the herein studied species to help setting a more precise taxa delimitation. Acetolyzed pollen grains were measured, described and illustrated using light and scanning electron microscopy. The pollen grains were medium or large sized, oblate spheroidal, suboblate, prolate spheroidal and subprolate; 4-colpate (P. kermesina), 6-12-pantocolporate (P. mediterranea), 6-colpate (P. mucronata), 6-colporate (P. pentagona), 12-colporate (P. misera) or 6-syncolpate (in most species). The presence of reticulate sexine, pseudopercula, pontopercula and/or opercula was observed. The endoaperture was just found in P. pentagona and P. misera. It was concluded that pollen morphology is an important source of taxonomic features useful for distinguishing species and characterizing the three subgenera. The current study provides additional information that, along with other previously published studies, will enable a better understanding of phylogenetic relations among these strains.