ABSTRACT
A new narrow endemic species of Begonia from the Atlantic rain forest of Brazil is described and illustrated. Begonia lunaris is known only from the type locality, Estação Ecológica Estadual do Paraíso, localized in the Municipality of Guapimirim and Cachoeiras de Macacu, Rio de Janeiro, Brazil (22º26'-22º32'S e 42º50'-42º56'W), growing near rivers. It promptly differs from the other Brazilian species of the genus in having wings of the capsule bent inwards, orange to orange-red flowers and crescent-shaped leaves. Diagnostic characters, description, detailed illustration and taxonomic comments are given and its relationships are discussed.
Key words:
taxonomy; atlantic forest; endemism