Island; taxonomy; floristic; Amazon; epiphytes.

The state of Pará is the second largest state in the Amazon. Among its geological formations, the continental islands stand out, formed through erosive processes resulting from geological periods. Islands are fundamental

for the preservation of species and plant communities, as they serve as a model of continental diversity and exhibit high diversity and endemism of vascular plants. In the state of Pará, studies on island biodiversity are still incipient. In the municipality of Belém, the state capital, the area occupied by islands exceeds that of the continental region and also has greater coverage and a higher number of forest remnants. Orchidaceae is represented by 378 species in Pará, and specific studies have revealed the richness of the family on Combu Island, one of Belém’s 39 islands. This study arises from the need to document the diversity of Orchidaceae in the island region of Belém through a floristic-taxonomic study, including an identification key for the species, descriptions, illustrations, photographs, data on local geographic distribution and habitat, as well as ecological and taxonomic comments. This study is essential to understanding the distribution and diversity of orchids on these islands, and it may highlight how biogeographic factors such as isolation, size, and distance from the mainland can influence these patterns. Initially, a survey was conducted in the collections of the herbariums

HBRA, HCP, HF, IAN, and MG and on the online platforms Specieslink, GBIF, JABOT, and Reflora. Additionally, field collections will be carried out from June 2024 to October 2025. Fertile material will be collected for deposition in the MG herbarium, with duplicates sent to IAN and HF. Sterile specimens will be collected for cultivation at the Orchidarium of the Epiphytes Research Center, located at the Federal Rural University of the Amazon – Capitão Poço campus. Descriptions will be based on pre-existing herbarium collections and newly collected materials. So far, 25 orchid species have been recorded in the island region of Belém, distributed across 19 genera, with nine still identified only at the generic level. The most representative genus was Epidendrum L., with three species, followed by Catasetum Rich. ex Kunth, Encyclia Hook.,Polystachya Hook., and Vanilla Juss., with two species each. New records include 13 epiphytic orchids, two hemiepiphytes, and one terrestrial orchid for Belém, with noteworthy species such as Caluera surinamensis Dodson & Determann, Gongora quinquinervis Ruiz & Pav., and Platystele ovalifolia (H. Focke) Garay & Dunst, which have few collected specimens in the state. So far, the survey reveals the rich biodiversity of orchids in the island region of Belém, differing from the already documented continental composition of the city. The study demonstrates that collection efforts and taxonomic identification help to understand species distribution patterns in island environments, which can support local conservation and awareness efforts regarding the dynamics and use of forest resources that house Orchidaceae species.