Araceae of Grumari restinga: contribution to the conservation of the flora of Rio de Janeiro State, Brazil

ABSTRACT This study surveyed species of the family Araceae in Grumari restinga, located in the metropolitan region of the city of Rio de Janeiro, Brazil. We aimed to: i) evaluate the contribution of a single locality (Grumari restinga) to regional conservation (Rio de Janeiro State) of Araceae; and ii) compare the distribution of species of Araceae among restingas of the state. We calculated the extent of occurrence and the area of occupancy in the entire state for eight species of Araceae found in Grumari,and performed a similarity analysis among restingas. Our data demonstrate that the extent of occurrences for Anthurium augustinum, A. coriaceum and A. maricense are influenced by Grumari because this area is the boundary of their known distribution in the state. Grumari did not have an influence on the distribution of the other studied species. We found Anthurium coriaceum, A. luschnathianum and Philodendron crassinervium to exhibit unusual habits as terrestrial plants in sandy soil. The similarity analysis identified six groups of Araceae, four of which are related to the distance from adjacent forests. We demonstrated that this small conservation unit represents a key locality in the preservation of natural populations of species of Araceae in Rio de Janeiro State.