Widespread. Asia, North, South and Central America, Caribbean, Oceania. In many Pacific islands.
Invasive, grows in shade and full sunlight, in disturbed places and fertile (Oceanic island) soils. Forms dense stands from root suckers in pastures, plantations, along streams, and at forest edges.
Perennial shrub up to 3 m tall. Stems and branches four-sided with fine hairs. Leaves, 6-20 cm long, opposite, heart-shaped, soft short hairs, wavy margins and sharp tips. Disagreeable smell when crushed. Flowers, 2-3 cm across, white to pink, double, sterile, in dense cluster at tops of stems. Fragrant in the evening.
Spread: root suckers; trade in ornamentals.
Biosecurity: high risk of introduction. Available on internet.
Biocontrol: potential with chrysomelid beetle, and fungal rust. Need to check identification of weed in Pacific.
Cultural control: hand weeding, digging, slashing, cultivation (probably not successful in wet soil).
Chemical control (from literature): (i) foliar (picloram; triclopyr; 2,4-D; metsulfuorn-methyl; picloram + triclopyr; picloram + 2,4-D; dicamba + 2,4-D); (ii) cut-stump (same herbicides); (iii) soil (fluroxypyr). In Fiji, glyphosate or metsulfuron-methyl.