Amazonia occupies approximately 60% of Brazil and hosts one-third of the country’s orchids. Pará state contains a significant portion of the Brazilian Amazon, the orchidological flora of which has become better documented in the last few decades. The municipality of Abaetetuba comprises several islands predominated by floodplain forest of ombrophilous broadleaf species interspersed with palm trees, especially the açaí palm known as “açaizeiro” (Euterpe oleracea). The species is of great importance to the riverside population and local economy since açaí is the main cultivated product of vegetal origin in the Amazonian estuaries. The opening of new areas for planting and intensive management of “açaizeiro” have a direct influence on local floristic diversity, with subsequent impacts on the epiphytic synusia. This work reports the results of a floristic-taxonomic study of Orchidaceae in floodplain areas of the islands of the municipality of Abaetetuba, Pará, Brazil. A total of 26 species were recorded. Seven species represent new occurrences for the municipality: Christensonella uncata, Eulophia alta, Lockhartia lunifera, Notylia aromatica, Oeceoclades maculata, Pleurothallis pruinosa and Scaphyglottis reflexa. Epiphytic and hemiepiphytic species (92.3%) prevailed over terrestrial species. Most of the holoepiphytes were collected on large trees with rough bark and of commercial interest, such as Hevea brasiliensis (“seringueira”) and Mangifera indica (“mangueira”). Only two species (Catasetum macrocarpum and Vanilla mexicana) were observed on açaí palms, which have a smooth stipe and an unbranched canopy, morphological characteristics we identify as being not favorable for the establishment of epiphytes. Some holoepiphytic species may be threatened locally. We emphasize the need for studies aimed at understanding the effects of intensive açaí palm management on the regional orchid flora.

亚马逊地区约占巴西的60％，拥有该国兰花的三分之一。帕拉州包含着巴西亚马逊河的很大一部分，其兰花植物区系在过去几十年中得到了更好的记录。阿巴埃特图巴直辖市包括通过与棕榈树，尤其是阿萨伊棕榈称为“açaizeiro”穿插ombrophilous阔叶树种的漫滩森林（占主导地位的几个岛屿蔬食埃塔棕）。该物种对河沿人口和当地经济至关重要，因为açaí是亚马逊河口植物的主要栽培产品。开放新的种植区域和集约化管理“açaizeiro”对当地植物区系有直接影响，进而对附生神经突触产生影响。这项工作报告了在巴西帕拉州Abaetetuba市的岛屿洪泛区兰科的植物分类学研究结果。总共记录了26种。七个物种代表了该市的新物种：克里斯塔氏菌Uncata，Eulophia alta，Lockhartia lunifera，Notylia aromaa，Oeceoclades maculata，Pleurothallis pruinosa和Scaphyglottis反射。附生和半附生物种（92.3％）高于陆生物种。大部分古生植物都收集在树皮粗糙且具有商业价值的大树上，例如巴西橡胶树（“ seringueira”）和印度芒果（Mangifera indica）（“ mangueira”）。只有两种（Catasetum macrocarpum和Vanilla mexicana）在açaí棕榈树上观察到，它们具有光滑的柄和无分支的树冠，我们认为形态特征不利于建立附生植物。一些杂生植物可能在当地受到威胁。我们强调需要开展旨在了解密集的印度棕榈树管理对当地兰花植物的影响的研究。