The monotypic genus Oceanopapaver is an endemic shrub found growing on serpentine soils in New Caledonia. Since its description in 1932, O. neocaledonicum Guillaumin has been placed in at least five families, including Capparaceae, Cistaceae, Oceanopapaveraceae, Papaveraceae and Tiliaceae. The chloroplast genes rbcL and ndhF were sequenced and phylogenetic analyses performed to clarify the taxonomic placement of this genus. The results strongly support the inclusion of Oceanopapaver in a clade of former Tiliaceae, the Grewioideae (Malvaceae s.l.). Within Grewioideae, Oceanopapaver forms a well-supported clade with representatives of the pantropical genus Corchorus and the endemic Malagasy genus Pseudocorchorus. This placement was anticipated by Tirel et al. (1996) who, based on morphology, reduced Oceanopapaver to a synonym of Corchorus. Morphological characters consistent with this placement include stellate indumentum, mucilage canals, valvate sepals with stellate hairs on the adaxial surface, and pollen morphology.

Key words: Malvaceae, Malvales, Oceanopapaver , Tiliaceae