Flat-top mille graines enjoys a wide range extending across several continents including Africa, Asia, and South America where it is native to various regions. The plant has also been introduced to Central America, the Caribbean, and parts of the Middle East. In its introduced range, which spans some Pacific Islands as well as Southeast and East Asia, flat-top mille graines may be sometimes thought to be established outside of its natural habitat. There, it can potentially have an impact on local ecosystems, particularly in areas where it is considered invasive.

Flat-top mille graines originates from tropical and subtropical Asia. It's considered a weed due to its rapid growth rate and ability to reproduce through an excessive number of seeds, which are easily carried by wind and water. This plant's seeds are extremely viable, leaving a damaging everlasting impact on gardens as they crowd out other plants. Due to its invasive nature, it consumes vital space, light, and nutrients meant for other plants, imposing negative effects on biodiversity. Particularly harmful to gardens, flat-top mille graines has the potential to drastically lower the productivity and aesthetic value of the cultivation. Its main method of spreading is through seed dispersal facilitated by wind and water, which leads it to invade even very distant gardens.

The ideal time to remove flat-top mille graines is during the spring season, before it begins to flower and its seeds start to spread. This prevents the weed from producing more seeds that could potentially populate the area.