Ocimum labiatum, at some stage known as Orthosiphon labiatus and commonly as the shell bush or pink sage, is a semi-deciduous, much-branched, rounded and hairy shrub reaching heights from 60 cm to 1,8 m.
The aromatic leaves grow on slender stalks, up to 3 cm long. They are heart-shaped with coarsely toothed margins. The deep green to yellow-green blades are sparsely hairy on top, long-haired below. Leaf dimensions is 3 cm to 8 cm long and 2 cm to 6 cm wide. The mint-like leaf scent is unpleasant.
The flowers grow in terminal clusters of up to eight in inflorescences of 5 cm to 18 cm long. The calyx is reddish mauve. The two-lipped pink to mauve flowers have their stamens far exserted. The flower is about 1 cm to 2 cm long. Flowering happens from summer to early autumn.
The species distribution is in the northeast of South Africa, occurring in KwaZulu-Natal, Mpumalanga, Limpopo and North West, as well as in some neighbouring countries. The habitat is dry, rocky hillsides. The species is not considered to be threatened in its habitat early in the twenty first century (Pooley, 1998; http://redlist.sanbi.org).