Rediscovery of Exallage auricularia (Rubiaceae) from Yonaguni Island, Okinawa, Japan

Abstract

Exallage auricularia (L.) Bremek. was rediscovered in Yonaguni Island, Okinawa, Japan after about 40 years. Exallage auricularia is morphologically variable to the extent that some varieties were proposed. The present phylogenetic analysis showed that the species may not be monophyletic as indicated in previous studies and that the plant in Yonaguni Island was closely related to those in Thailand and Fiji with moderate support. Further phylogenetic analysis is required to elucidate the relationship within the species and among closely related species.