Loganiaceae no estado do Rio de Janeiro: Chave para os gêneros e taxonomia de Spigelia

Abstract

Loganiaceae includes about 350 species arranged in 13 genera with pantropical distribution. Spigelia, with ca. 90 Neotropical species, is one of the most diverse genera in the family. A total of 54 species of Spigelia are known to occur in Brazil, thusmaking the country the genus' diversity center. Fruit morphology in Spigelia has been already considered, nevertheless, little attention has been given to the morphology of the basal differentiated portion of the fruit, the carpoatlas. This study presents a key to the genera and the taxonomic treatment for Spigelia in the state of Rio de Janeiro, focusing on the morphology of the carpoatlas. Nine species are accepted, with S. reflexicalyx being reestablished in the present work. All species are described, illustrated and commented, together with a distribution map and an identification key. The carpoatlas, foramen and stigma were shown to vary greatly in shape and size among the studied species.