Linnaeus invented a good system for the naming of plants. The botanic code regulates how plant names must be written. Seemingly, all problems are now solved. However plant names sometimes change. This has happened for example with a group of plants which everyone always has known under the Latin name Datura. Datura is now split up in Datura (upstanding flowers) and Brugmansia (hanging flowers).

Why do plant names change? The first reason is research. New scientific insights about relationships sometimes lead to changes in classification of plant groups. Thus it can happen that a researcher finds new evidence that a certain species belongs to another genus than to the genus in which this species was formerly recognised. This especially happens with genera which resemble each other a lot. Sometimes after research it becomes clear, that a certain group (family, genus, species) should rather be split up in two or more groups. Also it might happen that according to research two or more species rather be lumped into one species. Another reason why plant names change is because of errors made in the past. Especially the priority rule of the botanic code leads to name changes on a regular basis. Sometimes a taxonomist finds a name in a book which is older than the name which was always used for that plant group. According to the priority rule of the botanic code one has to change the newest name of that plant group into the oldest name.