The main Museum news stream features an article on the diversity of potatoes, referring to a paper produced by Dr Sandra Knapp and collaborators in Russia and the USA. They refer to the 626 different names (both species and varieties of species) used to refer to cultivated potatoes that are in fact members of only four species.
It's tempting to see this diversity of names as a mistake, or untidiness in taxonomy. The reality is more complex: the idea of what a species is and how it should be identified and named has changed over time. In addition, cultivated strains are frequently bred to develop particular characteristics that may have appeared to scientists in the past to represent different species. The fact that we are now able to bring together information on physical morphology with DNA data means that ideas of species can be tested in a number of different ways and reasons for superficial differences associated with cultivated strains explained.
ANNA OVCHINNIKOVA, EKATERINA KRYLOVA, TATJANA GAVRILENKO, TAMARA SMEKALOVA, MIKHAIL ZHUK, SANDRA KNAPP and DAVID M. SPOONER Taxonomy of cultivated potatoes (Solanum section Petota: Solanaceae) Botanical Journal of the Linnean Society Volume 165, Issue 2, pages 107–155, February 2011DOI: 10.1111/j.1095-8339.2010.01107.x