The Psoralea/Orbexilum post raised a recurring debate I have with myself. At what point do you accept or reject changes in nomenclature? I strongly believe that science is one of the most democratic of endeavors in which one can be involved. I say this based on the notion that science is based on peer review and the general acceptance (or the failure of rejection) of ideas by a group of informed people. However, the inevitable slop that is inherent to ideas and proof easily, and often, muddy the waters.
Having become a student of botany and Midwestern flora in the late 1990's, I had to jump in and learn whatever names were given by my mentors and/or the current flora in use for the region. And I did so with little questioning simply because one doesn't realize how much grey area exists until one gains familiarity with the sticky issues.
Case in point; the Psoralea/Orbexilum situation. If you were a botanist before 1930 (prior to the switch from the American Code of Botanical Nomenclature to the International Code of Botanical Nomenclature) there were many names like Orbexilum that you are seeing come back into usage. Also, there are names that have changed more recently such as Aster/Symphyotrichum. So the question is, how do you (and by "you" i mean YOU specifically and not in the collective sense) know what name to use?