Revision of Kadua (Rubiaceae) in the Marquesas Islands, French Polynesia, with description of the new species K. lichtlei

Abstract

Kadua lichtlei Lorence & W. L. Wagner, sp. nov., a new species from Ua Huka, Marquesas Islands, is described and illustrated. This new species differs from the three other Marquesan Kadua species by its broadly elliptic to broadly ovate or subcircular leaf blades as well as much smaller and more numerous (80-300) flowers and smaller capsules. Known from a single population of about 30 individuals, we conclude this new species should be added to the IUCN Red List as critically endangered (CR). A key, amended descriptions, conservation status, and specimen citations for the three previously described Marquesan species, Kadua lucei, K. nukuhivensis, and K. tahuatensis are also provided.