The family Orchidaceae in the Serra do Japi, São Paulo, Brazil

Abstract

This study reports the floristic survey of orchid species occurring in the Serra do Japi, State of São Paulo, Southeastern Brazil. The region is characterized mainly by semi-deciduous mesophytic lowland and altitude forests and rocky outcrops. The family is characterized by 125 species distributed among 61 genera. The most representative genus is Epidendrum (10 spp.), followed by Oncidium and Habenaria (both with 9 spp.). Most of the species (79 spp., 63.2%) occurs as epiphytes, while 40 species (32%) are terrestrial, 31 species (24.8%) are rupicolous, two are hemi-epiphytes and only one is a saprophyte. The semi-deciduous mesophytic forest has the highest occurrence of species of Orchidaceae, with 70.9% (88 spp.) of the species. The majority of species flower in summer, between December and March. Two species, Habenaria sp. and Acianthera sp. were not identified and are possibly new to science. The Serra do Japi is strategically placed in the transition between interior semi-deciduous mesophytic forests and the Atlantic forest, presenting species from both formations. Although the orchid diversity is high, the region is affected by anthropogenic disturbance. The preservation and the integrated study is an urgent necessity, with social, economic and preservationist reflexes.