Abstract The species of the Passiflora (Passifloraceae s.s.) are distributed in tropical and subtropical regions and are of great ecological importance. The Serra do Mar is formed of large escarpments along Brazil’s east coast, between the States of Rio de Janeiro and Rio Grande do Sul. This study aims to point out occurrences of Passiflora species in herbaria along the Serra do Mar, in addition to evaluating the conditions of each specimen found. The richness and sample effort maps were prepared to establish the locations where the greatest numbers of species and records were encountered. We evaluated the relationship of species distribution through Canonical Correlation (CCA) and Quadratic Polynomial Analysis. We also evaluated the floristic composition using a cluster analysis. Calculations of the Extent of Occurrence (EOO) and Area of Occupancy (AOO) were performed for endemic species to the Atlantic Forest area occurring in the Serra do Mar. A total of 53 species, belonging to the Passiflora were found in the Serra do Mar. The States of Rio de Janeiro and São Paulo were the ones that recorded the greatest numbers of species and collection effort. The climatic variables Precipitation of the Driest Quarter and Annual Average Temperature are the most correlated to the distribution of Passiflora in the area. Twenty-two species are endemic to the Atlantic Forest area, and 21 are recorded as having some degree of threat on Official Lists. In this study, we present all the Passiflora species recorded for the Serra do Mar, the richness of species, including those endemics to the Atlantic Forest, demonstrates the importance of the area for conservation.

Resumo O gradiente altitudinal entre outros fatores abióticos, está diretamente ligado à diversidade e distribuição de espécies. Outro fator importante é o posicionamento da cadeia de montanha, visto que as vertentes continental e oceânica possuem características distintas e podem exercer influência sobre a composição da vegetação. O objetivo deste estudo foi compreender a distribuição dos organismos pertencentes à família Passifloraceae sensu stricto em um gradiente de altitude, com variação de 300 a 2.199 m, no Parque Nacional Serra dos órgãos (PARNASO), localizado no estado do Rio de Janeiro, sudeste do Brasil. Foram realizadas expedições em campo para registro e coleta do material nas diferentes altitudes do PARNASO. Mapas de distribuição foram elaborados levando em consideração o esforço amostral, o gradiente de altitude e a pluviosidade. Foram realizadas análises estatísticas para estipular o padrão de riqueza e abundância dentro das classes de altitude. Para as vertentes oceânica e continental foram realizadas análises de similaridade, agrupamento e nMDS. Além disso, foram feitos cálculos de Área de Ocupação e Extensão de Ocorrência para avaliar o status de conservação das espécies. Foram registradas 19 espécies de Passifloraceae. As altitudes intermediárias apresentaram maior riqueza (1.100–1.300 m). A similaridade entre as vertentes foi de 28%, relatando riqueza distinta em ambos os lados da montanha. Os dados encontrados delimitam a distribuição e a composição de espécies de Passifloraceae dentro do PARNASO, tornando-se uma ferramenta colaborativa para ações de conservação do Parque.

Abstract Altitudinal gradients, among other abiotic factors, are directly linked to species’ diversity patterns and distributions. Another important factor to be considered is the geographic position of a mountain chain, with oceanic and continental-facing slopes having distinct environmental conditions reflected in distinct phytophysiognomies. We examined the distributions of species of Passifloraceae sensu stricto along an altitudinal gradient (varying from 300 to 2,199 m.a.s.l.) in the Serra dos Órgãos National Park (PARNASO) in Rio de Janeiro state, southeastern Brazil. Field excursions were undertaken to record and collect specimens. Maps were prepared of the distribution of sampling efforts, taking into consideration altitudinal gradients and rainfall. The statistical analysis was made to define the patterns of richness and abundance within the altitudinal classes. Analyses of similarity, grouping and NMDS were made of the oceanic and continental slopes. A total of 19 species of Passifloraceae s.s. were encountered. The greatest species richness was found at intermediate elevations (1,100–1,300 m.a.s.l). The similarity index between the two exposure slopes was 28%, indicating distinct species compositions on different faces. Our data helps to define the distribution and species composition of Passifloraceae s.s. within the PARNASO, and should be useful for conservation actions there.