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Abstract Background Nectar gain and loss are important flower transitions observed in angiosperms, and are particularly common in orchids. To understand such transitions, the availability of detailed anatomical data and species-level phylogenies are crucial. We investigated the evolution of food deception in Epidendrum, one of the largest orchid genera, using genus phylogeny to map transitions between nectar gain and loss among different clades. Associations between anatomical and histochemical changes and nectar gain and loss were examined using fresh material available from 27 species. The evolution of nectar presence/absence in Epidendrum species was investigated in a phylogenetic framework of 47 species, using one nuclear and five plastid DNA regions available from GenBank and sequenced in this study. Results The presence or absence of nectar was strongly associated with changes in the inner epidermal tissues of nectaries. Nectar-secreting species have unornamented epidermal tissue, in contrast to the unicellular trichomes found on the epidermis of food deceptive species. Bayesian tests confirmed that transitions occurred preferentially from nectar presence to nectar absence across the Epidendrum phylogeny. In addition, independent nectar loss events were found across the phylogeny, suggesting a lack of constraint for these transitions. Conclusions Ornamented nectaries may play an important role in the deceptive pollination strategy by secreting volatile organic compounds and providing tactile stimuli to pollinators. The recurrent and apparently irreversible pattern of nectar loss in Epidendrum suggests that food deception may constitute an alternative evolutionarily stable strategy, as observed in other orchid groups.

A Reserva Particular do Patrimônio Natural (RPPN) Paiol Maria possui 76 ha de Floresta Ombrófila Densa Montana e está localizada no município de São Lourenço da Serra, São Paulo, Brasil, pertencente ao Corredor de Biodiversidade da Serra do Mar. Objetivando elaborar uma listagem florística das espécies vasculares não arbóreas ocorrentes na RPPN, foram realizadas coletas durante o período de junho de 2010 a setembro de 2011. Foram inventariadas 330 espécies, distribuídas em 84 famílias e 223 gêneros. Das espécies amostradas, quatro são consideradas ameaçadas no Estado de São Paulo. A análise de similaridade entre as espécies epífitas ocorrentes na RPPN e outras quatro áreas de Floresta Ombrófila Densa Montana localizadas na Serra do Mar reafirma a importância de fragmentos em regeneração secundária para o conhecimento e conservação da biodiversidade da Floresta Atlântica.

Floristic sampling was carried out in Serra do Japi Biological Reserve, Jundiaí, state of São Paulo, Brazil, including physiognomies of semideciduous montane forest, a type of forest formation within the Atlantic Forest domain. Six hundred and sixty one species distributed in 129 families were recorded; the ten most diverse phanerogam families were: Asteraceae (56 species), Fabaceae (37), Rubiaceae (29), Poaceae (25), Solanaceae (24), Cyperaceae (19), Euphorbiaceae (19), Orchidaceae (19), Melastomataceae (17), and Piperaceae (17). The addition of 322 species from other floristic surveys increased the number of species of Serra do Japi to 976, distributed in 141 families. Compared to other floristic surveys carried out in the Atlantic Forest, our results highlight the floristic diversity of the study area and the importance of preserving the vegetation of this highly urbanized region.

Resumo Este estudo taxonômico envolve as espécies de Marantaceae registradas para as cangas da Serra dos Carajás, Pará, Brasil. Duas espécies ocorrem nas áreas de canga: Maranta ruiziana e Monotagma plurispicatum. Descrições morfológicas dos gêneros e espécies, ilustrações e comentários são apresentados.