Ferns and lycophytes in the Cerrado: a floristic study in eastern Maranhão, northeastern Brazil

The present study contributes to the knowledge of the fern and lycophyte flora of the city of Chapadinha, an area of the Cerrado located in the eastern state of Maranhão, Brazil. The study also presents taxonomic and environmental data on the occurrence of these species. Species were collected during five expeditions performed between December 2021 and August 2022, in two protected areas and some sites associated with wet environments outside these areas. In addition, specimens deposited in an herbarium were examined. In total, 20 species of ferns and three species of lycophytes were recorded, distributed over 12 families and 16 genera. The most representative families were Pteridaceae (six species) and Thelypteridaceae (four species). Despite the anthropization, riparian forests showed the highest richness (21 species), among which the non-flooded riparian forests stood out (18 species). Our data highlight the importance of identifying fern and lycophyte species and emphasize the potential of these species in future conservation studies and as ecological bioindicators.

Key words:
bioindicators; flora; inventory; vascular plants; taxonomy