The tribal placement of the monospecific tropical African genus Petitiocodon (Rubiaceae) based on molecular data and morphology

A first phylogenetic placement of Petitiocodon based on molecular sequence data from three plastid regions (accD-psa1, rpl16 and trnL-F) is presented, in conjunction with a reassessment of morphology for the genus. Our results do not support an evolutionary affinity between Petitiocodon and Tricalysia (Coffeeae) as suggested by previous studies, but they confirm other research that Petitiocodon and Didymosalpinx are distinct genera. Placement of Petitiocodon in tribe Octotropideae is well-supported on the basis of molecular data and floral and carpological characters.