Youngia japonica (oriental false hawksbeard).
Abstract Youngia japonica is a cosmopolitan herb that often grows as an agricultural and environmental weed. Native to temperate and tropical Asia and Australia, it has been introduced in Africa, the Canary Islands, the Americas and many Pacific Islands. It is commonly found in disturbed areas, wastelands, roadsides, abandoned pastures, lawns, cultivated fields and forest margins, but it is also able to penetrate into intact or minimally-disturbed natural areas. This species is a prolific seed producer and its seeds can be easily dispersed by wind and water or as contaminant in soil or crop and grass seeds. Y. japonica is adapted to grow in a wide range of climates and substrates and once it reaches a new area, it grows and spreads very quickly as new seeds are produced copiously.