- Worldwide distribution. In Australia, Fiji, French Polynesia, Guam, New Caledonia, Papua New Guinea, Samoa, Solomon Islands, and Tuvalu.
- Moderately invasive weed forming dense stands in gardens, parks, roadsides, wastelands, and low-growing vegetable crops. Combining rapid germination, short life cycle, massive seed production, and tolerance to different soil types and full sun. Alternate host of several fungal pathogens.
- Erect stem, up to 80cm, woody, 4-sided stems, hairy; leaves opposite, oval, pointed-tips short stalks, serrated margins; flowerheads yellow, arising from leaf axils, or end of stems, disc (inner) and ray (outer) florets, surrounded by leafy bracts. Seeds with bristles.
- Spread: seed on the wind, water, debris, clothing. Contaminant of crop seeds.
- Biosecurity: check for seed on clothing and vehicles.
- Biocontrol: none.
- Cultural control: hand-weed. Clean machinery/vehicles.
- Chemical control: in Australia, MCPA + terbutryn.
