Coleus is a genus of annual or perennial herbs or shrubs, belonging to the Lamiaceae family. Sometimes they have succulent leaves and stems, and sometimes they may even have a swollen rootstock. There are 29 species of Coleus occurring naturally in South Africa. Coleus are found in the summer-rainfall region of South Africa, mostly where frost is absent or light, in savanna, thicket vegetation, grassland, woodland, forest margins, coastal forest, afromontane forest, afrotemperate forest, often among rocks, on cliff faces, mostly in full sun, semi-shade or light shade, some in full shade. Coleus are fast-growing plants, often with a spreading or trailing habit and the ability to root as they grow, where their branches touch the ground. This allows them to quickly take advantage of favourable conditions, and to move into favourable positions. It also allows them to survive being trampled and/or grazed by various animals, where the broken-off branches can root and develop into independent plants. Many are succulent or semi-succulent, which enables them to survive periods of drought. Broken-off branches of the succulent species can also survive for a long time until rains fall, and they can form roots. Coleus flowers are pollinated by insects that feed on the pollen and nectar, such as bees, butterflies, carpenter bees and flies. The shape, length and colour of the flower tube influences which insects are attracted. Seeds are small, smooth nutlets inside the dried calyx, which are either shaken out and disperse around the mother plant or detach from the plant and are carried off by wind or passing animals.

Coleus argentatus, synonymously known as Plectranthus argentatus and commonly known as Silver Plectranthus or Silver Spurflower, is native to rock outcrops and rainforest in the border region of Queensland and New South Wales, Australia. Growing to 1 m tall and broad, it is a spreading deciduous shrub. The hairy leaves are ovate to broad-ovate, 5–11.5 cm long, 3–5.5 cm wide with crenate margins. The hairs give the plant an overall sage green to silvery colour. The flowers are borne on terminal racemes up to 30 cm long and are bluish white. Originally described by Queensland botanist Stanley Thatcher Blake, its specific epithet argentatus is Latin for “silver”, referring to its foliage.