**2.12.** *Plectranthus* **genus**

About 300 species distributed in tropical and warm regions of the old World, 45 species recorded in SA, from which 19 species were studied for their chemical and/or biological constituents. The genus is characterized by the presence of orange glands that distributed in the aerial parts and contain highly oxygenated (and modified) abietane-type diterpenoids. Others, e.g., kaurane, labdane, phyllocladane as well as the rare skeleton halimane diterpenoids were described.
