The threat from Chromolaena odorata and options for control.
The invasion of natural ecosystems by alien plant species is a serious environmental problem that threatens the productivity, biodiversity and ecosystem functioning. Chromolaena odorata is a weed native to tropical America and has become one of the world's worst alien invasive species in the Old World of tropical and subtropical countries. In invaded areas of the Old World, this plant has created many problems both in natural and disturbed ecosystems. To generate information useful for alleviating the problems, literature in Google Scholar, CAB Abstracts, Web of Science, PubMed and Scopus were searched. From those databases, reproduction, distribution and factors contributing to its success as an invader species are presented and discussed. Its threat to agriculture, natural ecosystem and animals are presented. Means of preventing the spread and controlling the growth of the weed are highlighted and discussed.