Exploring the diversity of ferns and lycophytes in the Jardim Botânico do Rio de Janeiro

Abstract

Abstract The Jardim Botânico do Rio de Janeiro (JBRJ) has an arboretum with 58 hectares of green space, including thematic collections. The ex situ collection of ferns and lycophytes is in two greenhouses: Mestre Valentim and the Shade Greenhouse of Horto Florestal. Although the JBRJ Arboretum is a cultivated area, it is adjacent to Parque Nacional da Tijuca (PNT), which is a fragment of the Atlantic Forest that may influence the flora in the garden. Specimens were collected and identified between 2020 and 2023 from all areas of the JBRJ, including the greenhouses. There are 101 species of ferns and lycophytes that belong to 47 genera and 24 families. Pteridaceae (21%) and Polypodiaceae (19%) are the most species-rich families. The collections in the Mestre Valentim and Shade greenhouses comprise 70 species, 35 genera, and 20 families. Five cultivated species are at risk of extinction: Adiantum mynsseniae, Dicksonia sellowiana, Anemia blechnoides, Doryopteris rediviva, and Pteris congesta. Most of the species inventoried in the JBRJ collection are native to Brazilian ecosystems (70%), including 10 endemic species. A list of species found in the JBRJ, with information about the location, distribution range, vouchers and type of occurrence (collection or spontaneous), is provided.