A perennial sprawling shrub with a creeping, weeping or trailing habit native to South America. Stems grow to about 1 m long. A weed of untended areas, replaces pasture species during times of prolonged drought. In Enoggera catchment, is widespread but not dense through drier areas.

Stems are slender, four-angled at first, later becoming more or less cylindrical. Branches root at the joints (nodes) and form dense mats over the ground surface. The leaves are oppositely arranged and aromatic when crushed with leaf stalks (petioles) 2-4 mm long. Leaf blades egg-shaped (ovate) with finely toothed margins. The upper surface of the leaves is rough to the touch, under surface is softly hairy. Flowers are tubular, borne in heads 1-2 cm across, initially mauve to pale purple with a yellow throat – later becoming more purple.

Photo: Robert Whyte

Fruit

Fruit is single-seeded, fleshy, green at first and red-brown when mature.

Class 3 declared plant in Queensland. Prohibited entry into Western Australia and the Northern Territory.

Photo: Robert Whyte