The genus Coleus (Lamiaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi), with the description of 15 new species

The genus <i>Coleus</i> is revised for DR. Congo, Rwanda, Burundi, based on herbarium taxonomy. Ninety-five taxa are reported (89 species, 1 subspecies, 5 varieties). Fifteen new species and one new variety are described (<i>Coleusduvigneaudii</i>, C.esculentusvar.kolweziensis, <i>C.hildei</i>, <i>C.kaminaensis</i>, <i>C.kundelunguensis</i>, <i>C.linarioides</i>, <i>C.lisowskii</i>, <i>C.marunguensis</i>, <i>C.minusculus</i>, <i>C.mitwabaensis</i>, <i>C.mystax</i>, <i>C.pengbelensis, C.piscatorum</i>, <i>C.pseudoschizophyllus</i>, <i>C.ruziziensis</i> and <i>C.zigzag</i>). Fourteen species are newly recorded in DR. Congo and two species are newly recorded in Burundi. Four new combinations are made (Coleusbetonicifoliusvar.kasomenensis, C.esculentusvar.densus, C.esculentusvar.primulinus and <i>C.parvifolius</i>). Ten names are lectotypified. One name is neotypified. Thirteen new synonyms are reported. Particular attention is paid to the <i>Coleusbojeri</i> complex. Three names are resurrected to accommodate the extensive variation patterns in Central Africa (<i>C.chevalieri</i>, <i>C.collinus</i> and <i>C.heterotrichus</i>); their distribution in Africa is outlined and the circumscription of <i>C.bojeri</i> is amended accordingly. Fifteen taxa are endemic to the study region. A determination key is provided.