Hello,
My suggestion is to contact
Dr. Lynn Clark of Iowa State University. One of her graduate students, Jimmy Triplett, recently presented at the American Bamboo Society Conference on "An Overview of Systematics and Evolution of
Pleioblastus - The genus
Pleioblastus Nakai is a group of approximately 42 species of temperate woody bamboos endemic to Japan, China and Vietnam..."
Since they're looking at the systematics of the group, they are likely to have the one of the best set of references in North America.
Best of luck,
Daniel