Résumé
Because of its complex taxonomic history, the identity, circumscription, and systematic position of Patima (Rubiaceae) have been nebulous. After a careful morphological analysis, Patima is here recognized as a monospecific genus endemic to the eastern portion of the Guayana Shield. Two names in Rubiaceae are here treated as new synonyms with Patima guianensis Aubl., Patima formicaria I. M. Johnst. and Hoffmannia megistophylla Standl. Two names described under Patima, P. laxiflora Benth. (here lectotypified) and P. forsythii DC. are shown to belong to other Rubiaceae genera. Aegiphila gleasonii Moldenke (described as a taxon in the Verbenaceae) is another new synonym of Patima guianensis. Patima is here included in the tribe Hamelieae (subfamily Cinchonoideae) because of its morphological features and its overall similarity to Hoffmannia. The presence of raphides in Patima (declared to be absent by previous authors) is here confirmed and discussed. A full account of the taxonomic history and systematic position of Patima, complete typification, complete generic and specific descriptions, a distribution map, a line drawing, photographs of raphides, and observations on ant/plant interaction are provided.