Review of Fiji Hibiscus (Malvaceae-Malvoideae) Species in Section Lilibiscus

The taxonomy of Hibiscus species in section Lilibiscus in Fiji is reappraised in the light of recent field and morphological studies. Six pre-European contact species are recognized. These comprise four Fiji endemic species, three of which are new and described: H. bennettii L.Thoms. and Braglia from Mt. Delaikoro, Vanua Levu; H. bragliae L.Thoms. from Ovalau; and H. macverryi L.Thoms. and Braglia from Macuata Province, Vanua Levu and Taveuni. The fourth Fiji endemic, Hibiscus storckii Seem., was first collected on Taveuni in 1860 and is here reinstated. Hibiscus cooperi Hort. Ex Lemaire, a species generally associated with the South Pacific region, has been confused in recent times with H. storckii. Hibiscus cooperi is lectotypified and reinstated. Hibiscus cooperi and H. rosa-sinensis L. are both considered ancient, pre-European introductions into the Pacific Islands. The Fiji archipelago is recognized as a secondary center of diversity and speciation in sect. Lilibiscus in the South Pacific. A botanical key is provided for the six Lilibiscus species that were present in the South Pacific Islands prior to European contact. All four Fiji endemic Lilibiscus species fall into the IUCN Critically Endangered (CR) Red List category and are highly threatened in the wild from climate change and associated extreme events including tropical cyclones, flooding, and landslides, as well as displacement by environmentally invasive species and through hybridization with introduced Hibiscus species. They are in urgent need of more intensive field survey followed by complementary in situ and ex situ conservation actions.