ABSTRACT The inflorescence of plants of the genus Typha L. consists of a polytelic system with the fertile region containing staminate flowers in the terminal portion and pistillate flowers in the basal portion. Although some useful morphological information has been provided to characterize species of the genus, various divergent typologies have arisen due to mistaken interpretations that ignore the different degrees of branching in this indeterminate system. The present study aimed to identify structural homologies by comparing the morphology and ontogeny of the synflorescences of Typha domingensis, T. latifolia and their putative hybrid, T. x provincialis, using standard micro-techniques for light and electron microscopy. Analysis revealed that the synflorescence of species of Typha should be considered a homothetic triple raceme. New diagnostic characters are proposed for both the pistillate and staminate portions. Differences among the apices of the pistillate portions are compared for the first time, and mainly involve the rate of lengthening of the second order branch, which is species specific. The data and interpretations proposed in this study should serve as a basis for proposing homologies for different structures of the synflorescences of species of Typha.

ABSTRACT This paper presents a morphological analysis of the flower and floral trichomes of three rare species of Dyckia: Dyckia ibicuiensis, D. polyclada and D. racinae. Flowers at anthesis were collected from natural populations and subjected to morphometric and microscopic analysis. Among the most representative features for Dyckia are: morphometrics of individual floral parts; the general configuration of the androecium and gynoecium; the degree of fusion of the stigmatic lobes; the morphology of the ovules, especially in relation to the chalazal appendix; and the presence and constitution of peltate trichomes in the perianth, which exhibited a polymorphism not previously reported for Dyckia. The characters were effective at describing each species, proposing phylogenetic inferences and recognizing infrageneric groupings. We propose two species groups, which are consistent with previous hypotheses about the relationships among the species of the genus. The objective of this study was to provide floral morphological data useful for characterizing these three rare species, delimiting the genus and forming phylogenetic hypotheses.

ABSTRACT This study presents a morphoanatomical analysis of Dyckia ibicuiensis , D. polyclada and D. racinae stamens. Flowers at anthesis were desiccated and their stamens were processed using common light microscopic techniques. Morphologically, the androecium in these species is differentiated by the disposition of the stamens around the gynoecium and by general anther characteristics. Included stamens, with antesepalous filaments different from those of the antepetalous, anthers in a radial disposition, always curved, and sporangia facing the gynoecium characterize D. ibicuiensis and D. racinae . This configuration results from the filament connation, as well as special anatomical characteristics of the anthers, such as the connective with thickenings. In addition, these species are differentiated by the U-shaped thickening in the endothecium. D. polyclada is characterized by its small, free and exserted stamens, with a very short common tube, its anthers, that are not curved or organized around the gynoecium, and its divergent sporangia. The anatomical and morphological characteristics identified here are important for characterization of these species. Considering that the androecium is important in the delimitation of Dyckia , the increased use of these data should be equally important for other species and infrageneric groupings.