Some species of Plectranthus are difficult to identify because of a lack of clear-cut morphological criteria to discriminate not only among species within the genus but also among the closely related genera. This has resulted in numerous taxonomic problems in the naming of species with the result that species have often been placed in several closely related genera like Coleus, Solenostemon and Englerastrum. In addition, some species formally placed in Plectranthus, are now recognized as the more distantly related genus Isodon.
Because of these taxonomic issues, different names have often been used for the same species of Plectranthus and thus it has been difficult to collate information about the ethnobotanical uses of this genus. Furthermore, the most commonly used medicinal species of Plectranthus have a high degree of synonymy[
This report is very much indebted to the work of C.W. Lukhoba et al. - Journal of Ethnopharmacology 103 (2006) 1–24[
] in untangling much of this mess of names, and utilizes the on-line Kew database ‘World Checklist of Selected Plant Families (http://wcsp.science.kew.org/home.do) for determining currently accepted names and synonyms (as of 2018).
Coleus mahonii Baker
Plectranthus mahonii (Baker) N.E.Br. ex Hook.f.
Plectranthus elegans is an erect, perennial plant[
The plant is harvested from the wild for local use as a medicine. It is sometimes grown as an ornamental.
Southern Africa - southern Malawi
The plant is anthelmintic, antibacterial and antifungal[
]. It is used as a treatment for digestive complaints and to alleviate sore throats[
]. It is also used to increase sexual potency[
Seed - sow in well-drained soil, covering lightly with a thin layer of sand, and place in a warm but shaded spot. The seed germinates in about three weeks[
Cuttings of Plectranthus species generally root easily - soft tips root faster than semi-hardwood growth. The cuttings are best taken 60 - 100mm long with three or four nodes, making the cut just below a node. Place them in sand, perlite, vermiculite or peat, or any mixture of these, keep them moist and shaded and they should root in 2 - 3 weeks[
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