To further muddy the waters try searching the Integrated Taxonomic Information System
http://www.itis.gov/
Note: You can read the Castanea article online for free on JStor. Create a free MyJstor account and save it to your bookshelf. You cannot download it for free although an institution such as a University or public library may be able to download it.
http://www.jstor.org/stable/4034104