Raritebe, an Overlooked Genus of the Rubiaceae

Abstract
Raritebe contains one species with two subspecies, the latter differing significantly in floral biology.Raritebe palicoureoides subsp.palicoureoides is heterostylous and is known from the Cordilleras Central and Oriental in Colombia and from east of the Andes in Ecuador and northeastern Peru;R. palicoureoides subsp.dwyeranum is homostylous and known only from west of the Andes in Colombia and from Panama and Costa Rica. The most probable hypothesis is that the selfincompatible subsp.palicoureoides gave rise to subsp.dwyeranum through genetic crossing over followed by long distance dispersal of the resulting self-compatible progeny. Coherent anthers with an unusual method of pollen release are characteristic of subsp.dwyeranum. Raritebe palicoureoides subsp.dwyeranum andR. palicoureoides subsp.palicoureoides var.antioquianum are described as new.