Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades.

Temnadenia odorifera is an endemic species from the Brazilian Atlantic Forest. This study was developed in order to identify the volatile compounds emitted by the living flowers and nectar, to evaluate the temporal pattern of scent emission, and the sugars composition of its nectar. Analyses of the flower scent by dynamic headspace in vivo, of nectar sugar composition and studies on floral biology were performed. Twenty-three volatile compounds were identified in the flowers scent. The total amount of odor emitted by flowers varied significantly throughout anthesis, ranging from 10232.7 ng g-1 (9 to 12 h) to 620.2 ng g-1 (15 to 18 h). 2-Phenylethanol and (E)-cinnamyl alcohol were the major compounds. Concentration ratio between disaccharides and the sum of hexoses ranged from 2.3 to 3.04, which can be correlated to the physiological needs inherent to big bees, the most frequent insects in T. odorifera. Analysis of the chemical composition of T. odorifera flowers provided a broader understanding of the mechanisms responsible for plant-insect interactions.

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(Reproductive assurance in three Neotropical species of Podostemaceae: strategies of self-pollination and the first report of apomixis). The aspects of reproductive assurance of the Lophogyne lacunosa (Gardner) C.P.Bove & C.T.Philbrick, Podostemum weddellianum (Tul.) C.T. Philbrick & Novelo, and Tristicha trifaria (Bory ex Willd.) Spreng. were investigated and, the mechanisms correlated to the flower morphology and floral biology. The mating system of L. lacunosa was also described, as well as the first report of apomixis in Podostemaceae. The reproductive assurance strategies used by L. lacunosa were autonomous competitive self-pollination, wind pollination, and apomixis. This species has floral attributes that ensure the dispersion of pollen by wind and its capture by the stigmas. Podostemum weddellianum and Tristicha trifaria presented autonomous competitive self-pollination before and during anthesis, respectively; both lack floral attributes for wind pollination. Considering that these species can be found in the same running water environment and that they are not phylogenetically close related, it was concluded that the different reproductive strategies are related to their evolutionary lineages.