Synopsis of the genus Ladenbergia (Rubiaceae)

Ladenbergia is a neotropical genus of the tribe Cinchoneae. It is recognized by the combination of septicidal capsules, usually large, winged seeds, heterostylous flowers, presence of terminal inflorescence, and distally ridged corolla lobes. Although widely distributed in tropical Central and South America, it is heavily centered in the Andes. II is hypothesized that the ancestral area was in the premontane zone of the central Andes. Thirty-four species are recognized in this revision, but several more are represented in herbaria by material that is too incomplete for formal description. Seven species are described as new: L. dwyeri, L. nubigena (Panama); L. klugii (Peru); L. lehmanniana, L. magdalenae, L. obovata, and L. pauciflora (Colombia). A key to the species is given, the new species are described, and distribution maps are provided for all species.