Japan, N. to Central China
"Many plants have mechanisms of physical or chemical resistance that protect them from herbivores in their environment. The ornamental plant Pachysandra terminalis is highly unpalatable to voles, but the nature of this resistance is not fully understood." 
"[Pachysandra] has been used extensively in Hubei Province, People’s Republic of China, as a Tujia traditional medicine against pain and stomach problems." 
"Pachysandra and other members of the Buxaceae contain alkaloids with antibacterial, antiviral, and anticancer properties." 
 Curtis, P. D., Rowland, E. D., Harribal, M. M., Curtis, G. B., Renwick, J. A., Martin-Rehrmann, M. D., & Good, G. L. (2003). Plant compounds in Pachysandra terminalis that act as feeding deterrents to prairie voles. HortScience, 38(3), 390-394.
 Van den Ende, W., Coopman, M., Clerens, S., Vergauwen, R., Le Roy, K., Lammens, W., & Van Laere, A. (2011). Unexpected presence of graminan-and levan-type fructans in the evergreen frost-hardy eudicot Pachysandra terminalis (Buxaceae): purification, cloning, and functional analysis of a 6-SST/6-SFT enzyme. Plant Physiology, 155(1), 603-614.
 Zhai, H. Y., Zhao, C., Zhang, N., Jin, M. N., Tang, S. A., Qin, N., ... & Duan, H. Q. (2012). Alkaloids from Pachysandra terminalis inhibit breast cancer invasion and have potential for development as antimetastasis therapeutic agents. Journal of natural products, 75(7), 1305-1311.