Besides the Atlantic Coastal Forest and the Brejos de Altitude in the state of Pernambuco, the eastern slopes of the Borborema plateau are also rich in species of Orchidaceae. Rocky outcrops are common and have been cited as one of the most representative sites for the family in Northeast Brazil. This study did a survey of the orchid flora on rocky outcrops in this state. Fieldwork was conducted from 2005 to 2013, and rocky outcrops from 13 different areas were visited. A total of 29 species and 18 genera were found. Habenaria (6 spp.) and Epidendrum (4 spp.) are the most representative genera. Of species recorded here, Acianthera prolifera and Octomeria alexandri are highlighted as new records for Pernambuco, and also Phragmipedium sargentianum which is on Brazil's endangered species list. The species are either widely distributed or have a restricted distribution; nine of these species are endemic to Brazil. This study confirms previous data on the great diversity and abundance of Orchidaceae in rocky habitats, including several endemic species. However, very few conservation units in Northeast Brazil contain this important ecosystem.
Caatinga; montane ecosystems; flora; Atlantic Forest; inselbergs
