Search

Although habitat destruction and the introduction of exotic species are causing the extinction of many native species, the number of extinct species that are then rediscovered is surprising. However, before searching for meaning of rediscoveries, we should distinguish between a false and a true rediscovery to avoid the interpretation of changes in biodiversity knowledge as changes in the efforts to conserve biodiversity. Here, we proposed the hypothesis of the biodiversity knowledge gap and a conceptual scheme to test this hypothesis, discussing how to deal with the rediscovery of a putatively extinct species. In this paper, we dealt with the local rediscovery of the plant Neptunia pubescens Benth. (Fabaceae), hypothesizing that if its local rediscovery is a case of the biodiversity knowledge gap (false rediscovery), its conservation status will change. Furthermore, we provided taxonomic data, geographic coordinates and figures as support for its local rediscovery, as well as some considerations about the implications for the conservation of N. pubescens.

AIMS: We offer a first classification of South Brazilian grasslands (Campos Sulinos) based on quantitative vegetation data and describing grassland types in terms of dominant and indicator species. LOCATION: South Brazilian grasslands (Parana, Santa Catarina, Rio Grande do Sul states). METHODS: We described vegetation plots in 167 sampling units throughout the region using a stratified nested design, totalizing 1,502 1 m² quadrats. We classified vegetation using cluster analysis based on Bray–Curtis dissimilarities, establishing three vegetation types and ten subtypes. We conducted indicator species analysis within the resulting subtypes, and for all possible combinations of subtypes. RESULTS: In the cluster analyses, a clear separation of poorly drained grasslands from the drier sites appeared. Further, a clear distinction between grasslands in the South Brazilian highland region, situated in the Atlantic Forest biome, and the grasslands of the Pampa biome, to the south, emerged, reflecting climatic and management differences. Highland grasslands showed lower species cover dominance, while in the Pampa, Paspalum notatum clearly was the most important species and the abundance of exotic species was higher. CONCLUSIONS: Our study provides the first classification of South Brazilian grasslands based on quantitative vegetation data recorded in a standardized sampling design. The data support the division of grasslands into the main phytogeographic units of the region (Brazilian biome classification). Grasslands in these two regions also differ in terms of species dominance pattern (higher dominance in Pampa grasslands, likely also due to higher grazing levels) and in terms of conservation state (low presence of exotic species in highland grasslands). Our results are important for conservation policies, which can now consider the presence of different grassland types in different region, but more data will be necessary for a more detailed classification that considers different abiotic features in more detail.

Megadiverse tropical and subtropical countries may be especially at risk from exotic species invasions. However, for these regions, the number of studies on invasive species is low. This paper aims at synthesizing knowledge on the alien herbaceous and shrub flora in the state of Rio Grande do Sul, southern Brazil, considering both presence of alien species in different vegetation types and availability of trait data. Our database is an extensive list of different studies that present vegetation data or species lists in the state. Trait data was gathered from a large number of sources. Only a small portion of alien plants was found with higher frequency in the analyzed studies, some of them species considered to be invasive. However, the data set available for our study clearly is biased towards well-conserved vegetation, and vegetation types that likely contain larger proportions of alien species have been poorly studied. On the basis of the existing data, it is impossible to assess impact of the large majority of the species considered to be invasive. Ordination analysis of alien species described by traits revealed no clear set of traits associated to species that are considered to be invasive, even though some broad patterns became obvious: C4 grasses of African origin, a group that includes several invasive species, were separated from the large majority of species, and very few invasives are among the large group of European forbs. Overall, we conclude that lack of data is a serious impediment to an evaluation of the risk posed by invasive species for the study region.

Resumo Hysterionica Willd. e um genero de Asteraceae pertencente a tribo Astereae, subtribo Conyzinae e esta estreitamente relacionado ao genero Neja D. Don. O genero posssui 11 especies restritas ao sul do Brasil, Uruguai e centro e norte da Argentina. O presente trabalho apresenta um estudo taxonomico de Hysterionica para o Brasil, sendo que foram registradas cinco especies: H. matzenbacheri A.A.Schneid., H. nebularis Deble, A.S.Oliveira & Marchiori, H. nidorelloides (DC.) Baker, H. pinnatiloba Matzenb. & Sobral e H. pinnatisecta Matzenb. & Sobral. Um novo sinonimo foi adicionado a H. nidorelloides (DC.) Baker: Hysterionica montevidensis Baker. Sao apresentadas chave de identificacao, descricoes, comentarios taxonomicos, ilustracoes, dados sobre floracao e frutificacao, distribuicao geografica e habitats de cada taxon e analise do nivel de ameaca das especies segundo criterios da IUCN. Hysterionica (Asteraceae: Astereae) in Brazil Abstract Hysterionica Willd. is a genus of Asteraceae and belongs to the tribe Asterae, subtribe Conyzinae and it is closely related to genus Neja D. Don. The genus has 11 species restricted to southern Brazil, Uruguay and north and center of Argentina. This work presents a taxonomic study about Hysterionica from Brazil, where five species have been recorded: H. matzenbacheri A.A.Schneid., H. nebularis Deble, A.S. Oliveira & Marchiori, H. nidorelloides (DC.) Baker, H. pinnatiloba Matzenb. & Sobral e H. pinnatisecta Matzenb. & Sobral. One new synonym was added to H. nidorelloides (DC.) Baker: Hysterionica montevidensis Baker. Identification key, descriptions, taxonomic comments, illustrations, data about flowering and fruiting phenology, geographic distribution and habitat of each taxon are presented and analysis of the threat level of the species according IUCN criteria.

Heiden G. & A. A. Schneider (2011). A new species of Baccharis sect. Caulopterae DC. (Asteraceae) from the high altitude grasslands of Parque Nacional do Caparao, Southeastern Brazil. Candollea 66: 337–340. In English, English and French abstracts. Baccharis hemiptera G. Heiden & A. A. Schneid., a new species of the high altitude grasslands from Parque Nacional do Caparao, southeastern Brazil, is described, illustrated and assigned to Baccharis sect. Caulopterae DC. The new species is close to Baccharis glaziovii Baker, from south-eastern and southern Brazil, and Baccharis subalata Wedd., from the Bolivian and Peruvian Andes.

Senecio madagascariensis Poir. is reported for the first time as an adventitious species in the process of getting naturalized in the Rio Grande do Sul state, Brazil. Description, illustrations and observations about this species are presented.

In this study, we describe the development and screening of an enriched genomic DNA library aiming to identify microsatellite loci in Hypochaeris catharinensis, an endemic species from southern Brazil. Twelve polymorphic microsatellite loci tested in a sample of 60 individuals from three different populations of H. catharinensis, identified 98 alleles with an average of 8.17 alleles per locus. The average polymorphic information content (PIC) varied from 0.098 to 0.757, with five loci exhibiting significant deviation from Hardy–Weinberg equilibrium (HWE). Transferability test for cross-amplification was done in 10 related Hypochaeris species with a rate of success ranging from 12 loci, for H. petiolaris and H. varigata, to six loci for H. patagonica. These microsatellite loci will provide valuable information for studying genetic diversity, population genetic structure, conservation biology and for understanding the past demographic events of H. catharinensis and other related species of Hypochaeris. Hypochaeris is considered as a biological model to understand evolutionary processes in the vascular flora of South America, particularly from the temperate portion of the continent. As suggested by molecular clock dating, the South American species of Hypochaeris was derived from a common ancestor from northwest Africa that arrived in the continent between 3.5 and 0.25 mya by long-distance dispersal

RESUMO - Este trabalho apresenta os resultados obtidos a partir do estudo morfologico em graos de polen do genero Pluchea. Este genero esta representado no Rio Grande do Sul por Pluchea laxiflora Hook. & Arn. ex Baker, Pluchea oblongifolia DC. e Pluchea sagittalis (Lam.) Cabr. Plantas deste genero podem variar de ervas a subarbustos, podendo habitar desde campos umidos ate locais arenosos. Foram estabelecidos tres padroes polinicos baseados nas diferencas da estrutura da exina e no tamanho da ornamentacao e da cava. Dados sobre o ambiente, ocorrencia das respectivas plantas, assim como aspectos da origem da familia Asteraceae e a taxonomia da tribo Plucheeae, sao aqui discutidos. Palavras-chave: Palinotaxonomia, Asteraceae, Pluchea, morfologia polinica.

A new species of Chevreulia (Asteraceae: Gnaphalieae) from southern Brazil is described in this work. Chevreulia revoluta A. A. Schneid. & R. Trevis. is characterized by leaves larger than seven mm long, opposite, divergent, linear, with upper surface glabrous and rostrate cypselae. A description is provided as well as a detailed illustration and taxonomic comments. In addition an analytical key to distinguish the species of the genus is included.

A new species of Baccharis L. sect. Caulopterae DC. (Compositae) of the high altitude grasslands of Southern Brazil is presented: Baccharis sphagnophila A. A. Schneid. & G. Heiden. The new species is described, illustrated and compared with similar species.

Porophyllum spathulatum is described and illustrated. The new species is distinguished by its decumbent habit, spatulate leaves and large heads bearing pale yellow florets. According to the collector’s information given on the labels, the plant was successfully recollected and is known to occur only in Balneário Hermenegildo, Santa Vitória do Palmar, Rio Grande do Sul, southernmost Brazil. Additionally, conservation status and ecological information about the new species are provided.

A new species endemic to rocky cliffs in southern Brazil, Hysterionica matzenbacherii, is described. This species is characterized by leaves that are distally irregularly incised to parted. It is morphologically similar to the Brazilian H. pinnatiloba and H. pinnatisecta in its habit, capitula and florets, but differs from them by its leaf features. A description of H. matzenbacherii , together with illustrations, a distribution map, habitat description, conservation assessment and diagnostic comparison with the other Brazilian species of Hysterionica is presented.

A new species of Baccharis L. sect. Caulopterae DC. (Asteraceae) from sandy soils and dunes on the coastalplain of Rio Grande do Sul state, Brazil, is presented: Baccharis dunensis A.A.Schneid. & G.Heiden. The newspecies is described, illustrated and compared to more closely related species. Additionally, B. burchelliBaker is reinstated, new synonyms are proposed for B. burchellii and B. crispa Spreng., and a lectotype isdesignated for B. regnellii Sch.Bip. ex Baker.Key words: Astereae, Baccharis subg. Molina, Compositae, Trimera group. Resumo Uma nova especie de Baccharis L. sect. Caulopterae DC. (Asteraceae) dos solos arenosos e dunas da planiciecosteira do litoral do Rio Grande do Sul, Brasil, e apresentada: Baccharis dunensis A.A. Schneid. &G.Heiden. A nova especie e descrita, ilustrada e comparada com as especies mais proximas. Adicionalmente,o binomio B. burchelli Baker e restabelecido, novos sinonimos sao propostos para B. burchellii e B. crispaSpreng., e um lectotipo e designado para B. regnellii Sch.Bip. ex Baker.Palavras-chave: Astereae, Baccharis subg. Molina, Compositae, grupo Trimera.