Sonia Marisa Hefler

Diversity of Cyperaceae in Brazil

Diversity of Cyperaceae in Brazil) The purpose of this catalogue was to combine the available data from publications, theses, databases, and herbarium specimens from around 120 Herbaria, and colections sampled in Brazilian vegetation during the last 15 years to produce the most complete list, as possible as, of Cyperaceae species for Brazil. We catalogued ca. 1,700 names for 678 species in 42 genera occurring in Brazil. These values represent ca. 15 percent of the species and 40 percent of the genera found in the world. Both subfamilies of Cyperaceae are found in Brazil with Cyperoideae being the most diverse at both generic and specific levels. Although lower species were recorded for the tribes Cryptangieae, Sclerieae, and Trilepideae, these tribes represent a much higher percentage of the worlds totals for genera and species. The most diverse genera are Rhynchospora (157 spp.), Cypents (101 spp.), Scleria (82 spp.) and Eleocharis (69 spp.). Fifteen genera have one species in Brazil, although five of them are monospecific. The most species-rich regions in Brazil are the North and Southeast. There are no genera endemic to Brazil. There are, however, around 200 endemic species, of which 40 are in the genus Rhynchospora. Taxonomic and nomenclatural problems found are pointed under the species. For each catalogued species, the principal synonyms, bibliographic references, distribution within Brazils five regions, vegetation type, and citation of selected material examined are provided.

Feeding ecology and basal food sources that sustain the Paradoxal frog Pseudis minuta: a multiple approach combining stomach content, prey availability, and stable isotopes

In the present study, we investigated ontogenetic diet shifts, feeding strategy, prey preferences, and basal food sources that sustain the Paradoxal frog (Pseudis minuta) based on stomach content, prey availability, and stable isotope (δ13C, δ15N) approaches. The feeding strategy analysis showed that the population can be considered a generalist species with each individual displaying a marked opportunism for different preys. Trophic positions estimated using nitrogen isotopic ratio (δ15N) revealed that tadpoles are primary consumers, but post-metamorphic individuals shifted to secondary and tertiary trophic levels as they increase in body size. A stable isotopic mixing model revealed that most of the carbon (0.61–0.72) sustaining the post-metamorphic P. minuta is derived from the aquatic rather than the adjacent terrestrial environment. This finding suggests that the post-metamorphic P. minuta is strongly dependent on carbon sources that primarily originate in aquatic systems, regardless of the terrestrial or aquatic origins of the arthropods in its diet. Our results indicated that this species is a generalist-opportunistic predator that derives most of their carbon sources from the aquatic environment where it shows preference for aquatic preys with higher individual biomasses.

A contribuição da anatomia foliar para a taxonomia das espécies de Cyperus L. subg. Cyperus (Cyperaceae) ocorrentes no sul do Brasil

The leaf anatomy of 15 taxa of Cyperus subg. Cyperus from Southern Brazil was analyzed aiming to find anatomic characteristics useful for identification. All the taxa studied have radiate chlorenchyma around the vascular bundles, Kranz anatomy of the Chlorocyperoid type and air cavities with starred cells in the diaphragms. The most important diagnostic characters are leaf-blade shape in cross section, arrangement and stratification of hypoderm and bulliform cells, degree of air-cavity development, and vascular-bundle arrangement. The results were useful to separate some exomorphologically similar species but were not conclusive for the definition of all specific or infra-specific complexes observed. On the other hand, the results reinforced the proposition of synonymies indicated by previous exomorphological analyses and micromorphological data of the fruit surface. The diagnostic value of the analyzed data is discussed and a comparative table is provided.

Composição florística e fitossociologia de macrófitas aquáticas em um banhado continental em Rio Grande, RS, Brasil

This work aimed to study the floristics and phytosociology of aquatic macrophytes in a continental wetland. A total of, 100 plots, (1 m2) were distributed systematically (intervals of 1 m), in 10 transects (20 m), in the Banhado 25 area (31°59’33”S; 52°17’32”O). Monthly collection data over a one-year period included observing plants “in loco”, collecting, identifying and classifying the plants according to habit and life form. For each species recorded we calculated absolute and relative frequency and coverage and importance value index (IVI). We analyzed the floristic similarity (Sorensen’s index) and applied linear regression. The survey yielded 82 species of vascular aquatic macrophytes, belonging to 33 families. In species richness, Cyperaceae (16 taxa), followed by Poaceae and Asteraceae (12 taxa each), showed greater contribution. The herbaceous habit (88%) and amphibious life form (94%) were the most representative. Scirpus giganteus Kunth had the highest IVI (27.58%). Higher coverage rates of this species showed a significant decrease in species richness (r2 = 0.503; p < 0.0001). The change in floristic composition between margin and interior of the wetland was evidenced by similarity analysis, forming two groups, possibly separated by humidity.

New records of bryophytes for the state of Rio Grande do Sul, Brazil

The aim of this study was to complete the species list and disseminate data regarding the diversity of bryophytes in the state of Rio Grande do Sul, Brazil. We registered 51 species of bryophytes (11 mosses and 40 liverworts) as new records for Rio Grande do Sul, of which six represent the second records for Brazil.

Sinopse da família Cyperaceae em uma área do extremo sul do Rio Grande do Sul, Brasil

This work was based on analysis of herbarium materials, bibliographic documentation and collections, covering all environments from an area of the coastal plain of the southern Rio Grande do Sul. We recorded 39 specific and infra-specific taxa distributed in 14 genera. Of these, the most representative were Cyperus L. with 11 taxa and Eleocharis R. Br., with 10.Keys are provided for identification of genera and species and comments on morphological aspects, habitat, distribution and phenology.