ABSTRACT
Humans have deliberately spread plants worldwide for millennia. The exchange of plants between different and often distant regions first became a mass global phenomenon in the post-Columbian era. Europeans introduced their cultivated and ornamental plants to the newly settled areas and in return made use of the biological wealth of the new regions for introductions into Europe (26,32,91,153). The scale of the introductions corresponded to the extent of the newly discovered regions. First Mediterranean and American species were usually introduced to central Europe, then species from Asia, and later Australian and African species (74,117).
