Worldwide distribution. In Australia, but NOT in Pacific island countries.
Aggressive weed especially in pastures (poor nutrition, overgrazed or following drought), cultivated land, open woodlands, grasslands, parks, wastelands, roadsides. Massive early (6-10 weeks) seed production. Environmental weed in competition with native species. Economic impacts from poisoning cattle (acute and chronic): lower carrying capacity, weed management, changing from dairy and beef to sheep/goats. Horses susceptible.
Spread: stems root from nodes, seed on the wind, birds, animals (including stock), on clothing, and contaminant (hay, other seeds, machinery, vehicles).