Plectranthus dolomiticus is a perennial, slightly succulent herb. It grows from tuberous roots into a rounded shape, about 30 cm tall. The greyish stems are hairy.
The leaves have petioles, are ovate, semi-succulent and nearly hairless. The mauve tubular flowers grow in cymes.
The plants grow from rock crevices in full sun in Mpumalanga and Limpopo (JSTOR).