ABSTRACT Distyly is a floral polymorphism that promotes cross-pollination through precise pollination. Psychotria is a mostly tropical genus of distylous Rubiaceae. Although widely studied in Brazil, some regions/species are still poorly explored, which hinders the understanding of distyly system along a greater geographical range. Here, we studied a subtropical population of Psychotria brachyceras in southern Brazil. For this, we characterized morphs occurrence, reciprocity of sexual structures, mating and incompatibility systems. In addition, we compared the reciprocity values from other species of the genus based on values gathered from literature to understand how the population behaves. The population showed equal proportions of thrum (short stigma/high anthers) and pin (high stigma/short anthers) morphs. Reciprocity was higher than the average for the genus and inaccuracy values between sexual organs were evenly distributed between the organ types, indicating a trend to typical distyly. Higher fruit set rates in intermorph and open pollination treatments and pollen tube growth observations confirmed that the population has a functional heteromorphic incompatibility system. Psychotria brachyceras showed no signs of distinct traits to typical distylous populations, which seems to ensure reproductive success and distyly maintenance.

ABSTRACT The relationship between plants and frugivorous animals is modulated by morphological and nutritional characteristics of fruits, as well as their seasonal availability across habitats. We evaluated fruiting phenology, fruit morphology and nutritional characteristics of 35 abundant plant species from 15 families associated with frugivorous birds from distinct habitats in the Cerrado (savanna, forest, and palm swamp). For a subset of 16 plant species, we also evaluated the overlap in interactions with frugivorous birds using data from the literature. Open-habitat plants had their fruiting peak during the rainy season, while fruiting of forest species was evenly distributed across the year. Plants of the same family exhibited similar fruit morphology and nutritional characteristics. Most plants had fruits with more sugars than lipids, while all species with higher lipid content were from savanna habitats and produced fruits during the rainy season, the peak reproductive season for birds. Assemblages of frugivorous birds exhibited considerable overlap, irrespective of habitat or fruiting season of plants. The complementarity found among habitats, considering seasonal availability and nutritional profile of fruits for frugivorous birds, is relevant for community maintenance and regeneration. Therefore, this landscape level complexity should always be considered in conservation and restoration policies for the Cerrado.

ABSTRACT Angiosperms display an enormous diversity of forms, functions and strategies when it comes to reproduction. This multiplicity has been translated into several terminological concepts and contexts, which have facilitated further research. On the other hand, the use of terms that address the reproduction of flowering plants has been shown to be inconsistent in the literature, complicating communication among specialists. Key terms, such as “reproductive system”, “mating system” and “sexual system”, among others, have been frequently cited as synonyms, and even used in different circumstances. This review proposes to establish a consistent nomenclatural classification in the field of angiosperms reproductive biology in order to facilitate communication among researchers. Specific terms related to angiosperm reproduction are conceptualized and distributed into five general systems: four related to sexual reproduction (sexual, floral, incompatibility and mating systems); and one related to asexual reproduction (apomictic systems). Our proposal is not to establish a natural classification, but rather to provide a general overview of the main concepts that were grouped here in an artificial and functional manner. Our aim is to advance the field of reproductive biology of angiosperms with consistent and well-defined applications of relevant terminologies.