Phylogeny of the tribe Cinchoneae (Rubiaceae), its position in Cinchonoideae, and description of a new genus, Ciliosemina

Relationships of and within the Rubiaceae tribe Cinchoneae were estimated based on DNA sequence variation in five loci: the ITS region, the matK and rbcL genes, the rps16 intron, and the trnL-F region including the trnL intron and the trnL-F intergenic spacer. Within Cinchonoideae s.s., the tribe Naucleeae is the sister group of a clade that comprises all other taxa. Cinchoneae and Isertieae s.s., are strongly supported as sister groups. The tribe Cinchoneae is strongly supported as monophyletic in a restricted sense, including the genera Cinchona, Cinchonopsis, Joosia, Ladenbergia, Remijia and Stilpnophyllum. There is strong support that these genera are monophyletic as presently conceived, except that one species mostly referred to Remijia is of uncertain phylogenetic affinity. To accommodate this species and a morphologically closely similar one, a new genus, Ciliosemina A. Antonelli, is proposed and two new combinations are made.