Palynology of Grewioideae species (Malvaceae sensu lato) occurring in the state of Rio de Janeiro, Brazil

Abstract The objective of this study was to characterize the pollen morphology of the Grewioideae species occurring in the state of Rio de Janeiro. Pollen grains of 12 species were examined: tribe Apeibeae (Apeiba tibourbou, Corchorus hirsutus, Triumfetta althaeoides, T. grandiflora, T. obscura, T. rhomboidea) and tribe Grewieae (Luehea candicans, L. conwentzii, L. divaricata, L. grandiflora, L. ochrophylla, L. paniculata). The pollen grains were acetolysed, measured, described and illustrated under light microscopy (LM). To observe the surface and opening, pollen grains not acetolysed were analyzed in scanning electron microscope (SEM) and subsequently eletromicrographs. Were characterized pollen grains as the shape, size, opening type, the polarity and the exina constitution. The analyzed species have pollen grains medium to large, isopolar, peroblate to prolate, 3-colporate and reticulated sexine. In pollen key, most species could be separated those attributes palynological. It allows consider that species which were studied here are euripolinic, since it is possible to recognize most species by palynological characteristics. It is believed that the present study provides pollen characteristics data that may help identify the species of Grewioideae that occur in the State of Rio de Janeiro.