Leo, For the botanist, knowing the collecting locality immediately rules out certain plants as well as literature that might be consulted. It is expeditious if nothing else. Many species are separated only by "technical characters" and these may not be readily ascertained in the field, as in the case of your Beaucarnea colleague. It is not cheating to rely partly on geography-- the point is to identify a plant accurately and by the most efficient means. If you have a specimen before you of, say, an Astragalus or Carex species (each genus with 1000++ species) then the practical importance of geography is at once appreciated. A somewhat humorous aside: I knew a botanist who struggled with the idea that there could be a single species that straddled the Andes (occurred both on the Pacific slope and in Amazonia), even though the morphology may have been so similar that writing a key to distinguish them was almost impossible. Dylan On 30 October 2012 14:42, Leo A. Martin <leo@possi.org> wrote: > My point was that the expert, even after examining the plant, was unable > to identify a species without knowing where he was. If that is the case, > how valid can the separation of this genus into species be? I have been > led to believe we name species based on differences in plant structures, > not geography. > > Leo Martin > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >