Plectranthus argentatus S.T.Blake Lamiaceae Silver spurflower. Herbaceous perennial. Distribution: Queensland and New South Wales, Australia. Little is known of its chemical constituents. It does contain many novel diterpenoids in its leaf glands (Alder, A.C. et al, Helvetica Chimica Acta, 2004, 67(6): 1523 – 1530).This genus has had some species from the genus Coleus incorporated into it, and these form a separate clade on phylogenetic analysis. The species in the ‘Coleus’ clade have a higher incidence of medicinal usage, being used to treat digestive, skin, infective and respiratory problems. They contain monoterpenoids, sesquiterpenoids, and diterpenoids. Photographed in the Medicinal Garden of the Royal College of Physicians, London.