ABSTRACT Situated within the Atlantic Forest domain, the Centro de Endemismo Pernambuco (Pernambuco Center of Endemism) - CEPE is regarded as a priority for biodiversity conservation worldwide. Covering an area of approximately 56,000 km2, it encompasses part of the states of Alagoas, Pernambuco, Paraíba and Rio Grande do Norte in northeastern Brazil. Here we present an identification key to 73 species of Myxomycetes that compose the known corticolous myxobiota of the Dense Ombrofilous Lowland Forest, Semideciduous Lowland Forest, Restinga Forest and Mangrove environments of CEPE. Specimens included here were found developed in natural conditions in the field or obtained through moist chamber culture. Among the species found, Arcyria cinerea, Clastoderma debaryanum, Cribraria confusa, C. violacea and Echinostelium minutum were the most common; and Comatricha longipila, Licea pedicellata, Paradiachaeopsis longipes, Perichaena calongei and Stemonaria fuscoides were the most rare. Our data indicates that the species richness of corticolous myxomycetes in rainforests is lower than that of temperate forests. These same data also suggest that taxonomic diversity (mean number of species per genus) is similar to, or higher than, that found in temperate regions of the world.

The known distribution of Perichaena calongei, P. chrysosperma, P. corticalis, P. depressa, P. microspora, P. pedata and P. vermicularis in the nine states that comprise Brazil's Northeast Region (1,548,672 km2) is presented herein, enhancing our understanding of the distribution of the genusPerichaena (Trichiaceae, Myxomycetes) in the Neotropics. This inventory encompasses a 100-year period (1914-2014), and analyzes material deposited in herbaria and collected by the authors. The collected material came from areas of thorny deciduous vegetation typical of the Caatinga biome and portions of savannah in the continent's interior, rainforests,restingas (tropical moist broadleaf forests found along Brazil's coastal spits) and mangroves of the Atlantic Forest biome along a coastal zone of approximately 3,000 km. Descriptions, illustrations, vegetational environments, microhabitats and distribution maps are given for each species. New records include Perichaena chrysosperma andP. depressa in the state of Maranhão, P. corticalis in the states of Bahia, Piauí, Rio Grande do Norte and Sergipe, P. calongei in the Northeast Region, and P. pedata in Brazil. This paper adds to the known types of macroclimates, elevation levels, vegetational environments and substrates for these species and provides a better understanding of their global distribution pattern.

Este trabalho apresenta uma revisão da coleção de Trichiaceae do Herbário SP, que abriga 128 exsicatas coletadas principalmente em Unidades de Conservação de Floresta Atlântica (Parque Nacional da Floresta da Tijuca e Parque Nacional do Itatiaia, Rio de Janeiro; Parque Estadual das Fontes do Ipiranga e Reserva Biológica do Alto da Serra de Paranapiacaba, São Paulo). Alguns espécimes foram coletados em Floresta Amazônica (Pará e Rondônia), Cerrado, ambientescosteirose áreas urbanizadas (MinasGeraise São Paulo). Acoleção de Trichiaceae encontra-se em boas condições de conservação, com seis gêneros e 15 espécies. Arcyria, com seis espécies, representa 60% de todas as exsicatas. Arcyria denudata (L.) Wetts. é um novo registro para o Estado do Pará, ampliando o conhecimento sobre a distribuição geográfica desta espécie na Amazônia brasileira. Uma lista comentada das espécies, incluindo o typus do gênero Arcyriatella Hochg. & Gottsb., é fornecida.

This article prese nts a review of the Trichiaceae collection of the SP Herbarium which holds 128 exsiccates mainly collected from Conservation Units of Atlantic Forest (Parque Nacional da Floresta da Tijuca and Parque Nacional do Itatiaia, Rio de Janeiro State; Parque Estadual das Fontes do Ipiranga and Reserva Biológica do Alto da Serra de Paranapiacaba, São Paulo State). Some specimens were collected from Amazon Forest (Pará and Rondônia States), Cerrado, (savanna-like vegetation), coastal environments, and urbanized areas (Minas Gerais and São Paulo States). The Trichiaceae collection is in well preserved conditions, with six genera and 15 species. Arcyria, with six species, represents 60% of all exsiccates. Arcyria denudata (L.) Wetts. is a new record for Pará State, enhancing the knowledge of this species geographic distribution in the Brazilian Amazon Region. A commented list of the species and exsiccates are provided herewith, including the typus of the genus Arcyriatella Hochg. & Gottsb.

The present study was carried out on three trails, each presenting a different degree of disturbance, within the Pau-Ferro Forest Environmentally Protected Area, a 600 ha area of highland forest located in the municipality of Areia (06°58'12"S; 35°42'15"W; elevation, 400-600 m), in the state of Paraíba, Brazil. In 2005, we analyzed the species richness, abundance, constancy and phenology of myxomycetes over seven consecutive months (rainy and dry seasons) in five types of microhabitats: dead tree trunks, the bark of living trees, basidiomata, ground litter and aerial litter. A total of 753 specimens of 48 species were obtained from the trails known as Flores (4 km), Boa Vista (3 km) and Cumbe (700 m). The Sørensen similarity coefficient revealed that the three trails are similar. The most constant and abundant species were Hemitrichia calyculata, H. serpula, Arcyria cinerea, A. denudata and Ceratiomyxa fruticulosa. Although myxomycetes sporulate throughout the year, some species have well-defined sporulation seasons. In terms of the constancy and abundance of species, Trichiaceae is the most important family in the rain forest studied, which is representative of the highland forests of northeastern Brazil.