Florística e ecologia das Orchidaceae das restingas do estado do Espírito Santo

Abstract

An inventory of the Orchidaceae of the coastal plain vegetation (restingas) of Espírito Santo State, Brazil, is presented here. The life forms were examined as well as the similarity between restinga vegetation types based on the orchid flora. Botanical material was collected along the entire coast and material from the following herbaria was examined: CVRD, MBML and VIES. A total of 73 taxa were identified, including two natural hybrids. Of the 71 remaining taxa, one was a new species. The most species-rich genera were Epidendrum (7) and Pleurothallis (6). The taxons were classified as follows: 31 holoepiphytes, 28 terrestrials, 12 facultative epiphytes and 2 hemiepiphytes. Orchid species are found in eigth of the 10 restinga vegetation types: sandy coastal forest (58), open Clusia scrub (31), open Ericaceae scrub (20), periodically flooded forest (14), closed beach-thicket (13), Palm scrub (10), sedge swamp (3) and creeping psammophytic (2). Highest floristic similarity based on Sorensen's index was found between the closed formations (beach thicket and Palmae scrub), followed by the open formations (Ericaceae and Clusia). These two groups are linked at lower similarity values with the forest formations, while the herbaceous formations are quite dissimilar.