Ecology of neotropical mistletoes: an important canopy-dwelling component of Brazilian ecosystems RESUMO (Ecologia de ervas-de-passarinho Neotropicais: um importante componente do dossel de ecossistemas brasileiros). Ervas-de-passarinho têm sim sido regularmente estudadas em países temperados por afetar negativamente espécies cultivadas e fl orestas manejadas. Em comparação com ambientes temperados pouco se conhece sobre a ecologia das ervas-de-passarinho neotropicais. Desta forma, é necessário maior conhecimento sobre o grupo porque são importantes elementos de comunidades vegetais, atuando como recurso-chave para polinizadores, dispersores de sementes e herbívoros. Através de uma combinação de trabalhos clássicos já publicados com evidências empíricas recentes, nós apresentamos padrões emergentes da interação entre ervas-de-passarinho com os organismos associados e questionamentos para estudos adicionais. Existe um crescente interesse neste grupo no Brasil. E embora existam informações sobre dispersão de sementes, estudos sobre biologia reprodutiva são raros e representam um campo a ser explorado. O conhecimento da biologia básica das ervas-de-passarinho será relevante para modelar sua distribuição espacial usando uma abordagem metapopulacional ou epidemiológica. Nesta revisão nós sumarizamos os principais estudos conduzidos na região Neotropical para fornecer um panorama atual das pesquisas desenvolvidas, bem como novas ideias para futuras investigações, especialmente no Brasil. Palavras ABSTRACT(Ecology of neotropical mistletoes: an important canopy-dwelling component of Brazilian ecosystems). Mistletoes have been studied in temperate countries regularly because they can be pests of cultivated plants and forest plantations. In comparison with temperate habitats, little is known about the ecology of mistletoes in the Neotropics. More emphasis should be given to neotropical mistletoes because they could be important elements of plant communities, acting as key resources for pollinators, seed dispersers and herbivores. Using a combination of fi ndings from early mistletoe studies and empirical evidence from several recent case studies, we report emerging patterns of mistletoe interactions with associated organisms and propose aims for further studies. Th ere has been increasing interest in working with mistletoes in Brazil. Although there are some data on the ecology of mistletoe seed dispersal, reproductive biology studies are scarce and represent a wide range of fi eldwork to be explored. Knowledge of the basic biology of mistletoes will be very important for modeling their spatial distribution using metapopulation or epidemiological approaches. In this review, we summarize the studies conducted in the neotropical region in order to provide a framework for current research and new ideas for future investigations of mistletoes, especially in Brazil. Revisão / ReviewActa bot. bras. 26(2): 264-274. 2012.Ecology of neotropical mistletoes: an important canopy-dwelling component of Brazilian ecosystems

-The goal of this work was to characterize morphometrically diaspores from three species of mistletoes (Passovia pyrifolia, Struthanthus marginatus e Phoradendron mucronatum), as well as to study its germination behavior according to temperature and luminosity. In germination tests, the completely randomized design was used, in factor scheme 4 x 2, with 4 replications of 15 diaspores. The factors for the first test were different temperatures and two diaspore conditions (intact and without epicarp). In the second test, factors were different light qualities and two diaspore conditions. The analyzed variables were: germination percentage, germination rate index (GRI) and mean germination time (MGT). Mistletoe's diaspores present an elliptic shape with viscin layer, an essential characteristic for the dispersion of the species. In addition to this, they present a distinction as for the moisture content when compared to the Loranthaceae and Viscaceae, where the latter presents the highest content. Germination is greater at the alternated temperature of 20-30 o C for P. pyrifolia and P. mucronatum diaspores and 20 o C for S. marginatus. Luminosity interfered in the germination of P. mucronatum and S. marginatus but did not influence P. pyrifolia. The diaspore condition influenced the germination of the three studied species, observing a significant increase in their germination when the epicarp was removed. Temperature and luminosity interfere directly in the GRI and MGT of the three mistletoes species.Keywords: mistletoes, temperature, luminosity. RESUMO -O objetivo deste trabalho foi caracterizar morfometricamente diásporos de três espécies de ervas-de-passarinho (Passovia pyrifolia, Struthanthus marginatus e Phoradendron mucronatum), bem como estudar o seu comportamento germinativo em função de temperatura e luminosidade. Nos ensaios de germinação utilizou-se o delineamento inteiramente casualizado em esquema fatorial 4 x 2, com 4 repetições de 15 diásporos. Os fatores para o primeiro ensaio foram diferentes temperaturas e duas condições do diásporo (intacto e sem epicarpo). No segundo ensaio, os fatores foram diferentes qualidades de luz e duas condições do diásporo. As variáveis analisadas foram: porcentagem de germinação, índice de velocidade de germinação (IVG) e tempo médio de germinação (TMG). Os diásporos de ervas

The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.

Mistletoe can have a major impact on the fi tness of the host plant. If there is more than one species of mistletoe on the same host tree, the overall impact might be amplifi ed. We report the occurrence of more than one species of mistletoe on the same host tree. Although it is not a rule in the fi eld, to our knowledge, there have been no studies of this topic. In most cases, two species of mistletoe were recorded on the same host tree, although we recorded three species of mistletoe on one occasion. Th is demonstrates that diff erent species of mistletoe can be compatible with the same host species. Th erefore, compatibility (structural and physiological) might be an important factor for the occurrence of mistletoe. Recent studies have shown that if the mistletoe does not "recognize" the host species, the deposited seeds will germinate but the haustorium will not penetrate the host branch. Th is is probably the primary mechanism in the establishment of more than one species of mistletoe on the same host, which can trigger a cascade of harmful eff ects for the host species.

The genus Peristethium, characterized by determinate inflorescences protected by deciduous bracts, occurs in the northwest of South America, as well as Costa Rica and Panama. The main objective of this paper was to transfer one species to what we believe is its correct generic placement in Peristethium, that likewise implies in a shift of the genus' distribution beyond the Amazon. A new combination, Peristethium reticulatum, is proposed, based on Struthanthus reticulatus, described from Tocantins in 1980. The sexual dimorphism of the inflorescences of P. reticulatum (sessile male flowers and pedicellate female flowers) associated with male inflorescences that are inserted at leafless nodes are unique within the genus. The male flowers have dimorphic stamens, well-developed anthers and a pistiloid, whilst female flowers have robust styles and stigmas, and much reduced staminodes. Peristethium reticulatum and P. polystachyum occurs in the Amazon regions of Brazil, with the former recorded also in the ecotone with the Central Brazilian savannas (Cerrados).

No abstract

RESUMO(Novos sinônimos e uma nova combinação em Pusillanthus (Loranthaceae)). Uma revisão de Pusillanthus Kuijt para o Brasil é apresentada. O gênero monotípico recém-descrito ocorre na Venezuela, Guiana e Brasil. No Brasil, distribui-se somente na Caatinga, nos estados de Alagoas, Bahia e Paraíba. A nova combinação Pusillanthus pubescens (Rizzini) Caires é proposta e as espécies Phthirusa caatingae Rizzini, Pusillanthus trichodes (Rizzini) Kuijt e Struthanthus pubescens var. bahiensis Rizzini são tratadas como seus sinônimos taxonômicos. Uma prancha ilustrativa e um mapa de distribuição para o gênero no Brasil são apresentados, bem como estudos da arquitetura foliar, de superfícies de caule, folha e grãos de pólen usando Microscopia Eletrônica de Varredura.Palavras-chave: arquitetura foliar, Brasil, Caatinga, ginomonoicia, Nordeste, Pusillanthus pubescens ABSTRACT (New synonyms and a new combination in Pusillanthus (Loranthaceae)). A revision of Pusillanthus Kuijt for Brazil is presented. The recently described monotypic genus occurs in Venezuela, Guyana, and Brazil. In Brazil, it is distributed only within the Caatinga domain, in the states of Alagoas, Bahia and Paraíba. The new combination Pusillanthus pubescens (Rizzini) Caires is proposed and the species Phthirusa caatingae Rizzini, Pusillanthus trichodes (Rizzini) Kuijt, and Struthanthus pubescens var. bahiensis Rizzini are treated as its taxonomic synonyms. An illustrative plate and a distribution map for the genus in Brazil are presented, as well as information about leaf architecture, and stem, leaf, and pollen grain surfaces (based on scanning electron microscopy).

We present results related to the taxonomic revision of Psittacanthus (Loranthaceae) for “Flora do Brasil 2020”. Three new records were found: Psittacanthus kempffii to Rondônia, P. lasianthus to Roraima, and P. truncatus to Mato Grosso. Twelve new synonyms are proposed here: P. carnosus, P. crassipes and P. pustullosus (synonyms for P. acinarius), P. duckei (for P. biternatus), P. baguensis (for P. crassifolius, P. salvadorensis (for P. excrenulatus), P. bergii (for P. grandifolius, P. brachypodus, P. leptanthus and P. redactus (for P. lamprophyllus), P. acevedoi and P. rugostylus (for P. plagiophyllus). Three lectotypes are designated: for P. lasianthus, P. rugostylus and P. biternatus, which makes the neotype previously designated for P. biternatus superfluous. The type-specimen of P. formosus (synonym of P. robustus) was recently found. We propose an identification key for the 33 Brazilian species, with illustrations of the main characters used.