The trumpet tree (Cecropia peltata) is a small weedy tree from humid tropical America, which was introduced to Africa around 1910. For half a century after introduction, the trumpet tree remained a welcome guest in West and Central Africa, spreading only very slowly, before it began to invade...

This paper briefly discusses the introduction of Prosopis species into Africa from their native America over the past 200 years. Although some are useful for fuel, fodder or erosion control, others have become invasive weeds. The first detailed study on the impacts (both positive and negative) of...

This paper briefly describes Parthenium hysterophorous, its origin, spread and its colonizing ability, and its biological control. Focus is given on its occurrence in Ethiopia, first reported in 1988, and the succeeding major infestations and eventual spread throughout the country. The importance...