Semi-woody herb up to 50 cm tall, aromatic. Solitary stem, very branched, hairy. Leaves up to 2.5 cm long, ovate to elliptic, sparse pubescent, glandular spiny base, attenuate base, with serrated edges distally. Flowers white or pinkish purple, shiny, with persistent underlying bracts, up to 5 mm, slightly puberulous; corolla 4 to 6 mm, tube 4 to 5 mm. Fruit with 4 nutlets 1.5 to 2 mm long, dark brown.
Distribution: native to the tropics of the Old World, frequently found in tropical America.