How does one determine why a plant's scientific name has been
changed in recent years? Is there some journal (online or not)
that is the official record-keeper of these changes?

I saw an usual vine in flower yesterday, and could not find it
in my Newcombe's wildflower guide. Fortunately it was in the
pictorial guide "Wildflowers of the Shenandoah Valley and Blue
Ridge Mountains" by Gupton and Swope, as Gonolobus obliquus.
Checking other, more recent references, (Vascular Flora of the
Carolinas, West Virginia Flora, plants.usda.gov), it appears
that this genus has been renamed to Matelea. I would like to
know when and why, and most importantly, the significance of
the term "Matelea."

-David Cox