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

Abstract

The genus Coleus 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 (Coleus duvigneaudii, C. esculentus var. kolweziensis, C. hildei, C. kaminaensis, C. kundelunguensis, C. linarioides, C. lisowskii, C. marunguensis, C. minusculus, C. mitwabaensis, C. mystax, C. pengbelensis, C. piscatorum, C. pseudoschizophyllus, C. ruziziensis and C. zigzag). Fourteen species are newly recorded in DR. Congo and two species are newly recorded in Burundi. Four new combinations are made (Coleus betonicifolius var. kasomenensis, C. esculentus var. densus, C. esculentus var. primulinus and C. parvifolius). Ten names are lectotypified. One name is neotypified. Thirteen new synonyms are reported. Particular attention is paid to the Coleus bojeri complex. Three names are resurrected to accommodate the extensive variation patterns in Central Africa (C. chevalieri, C. collinus and C. heterotrichus); their distribution in Africa is outlined and the circumscription of C. bojeri is amended accordingly. Fifteen taxa are endemic to the study region. A determination key is provided.