In Japan, Bizen province provides the Imperial Court drugs from medicinal plants, including peonies. These plants could not have been native, demonstrating that already domesticated peonies were in Japan by the 8th Century. One of the specific citiations is (pg 133) in Kubo, T, 2009. The problem of inentifying mudan and the tree peony in Early China. https://brill.com/view/journals/asme/5/1/article-p108_7.xml
