Palms Beyond the Forests: The Ex Situ Conservation at the Rio de Janeiro Botanical Garden

The Rio de Janeiro Botanical Garden (JBRJ) holds one of the most diverse ex situ palm collections among tropical botanical gardens. This study describes the current composition of the collection, its taxonomic breadth, and its relevance for conservation. In 2025, this inventory documented 1648 individuals from 71 genera and 153 species. About 21% of these specimens are native to Brazil and 76% are exotic, reflecting both historic introductions and the garden’s long tradition in palm acclimatization. The collection includes 17 individuals of 8 native threatened species and 57 individuals of 13 exotic threatened species. Accuracy at the species level improved from 84.2% to 93.3% after identification work, taxonomic revision, correcting misidentifications and standardizing nomenclature. The results reveal gaps in provenance information and a limited representation of native taxa, underscoring the need for targeted additions. Strengthening national partnerships, developing metacollections, and improving provenance records are proposed as key strategies to enhance the conservation value of this living collection. Overall, the JBRJ palm collection serves as an important scientific, educational, and conservation resource and plays a central role in advancing the ex situ preservation of Brazil’s palm diversity.