China, Japan, Korea
Styrax japonica is a possible honeybee plant. 
"Although familiar to American gardening connoisseurs for more than a hundred years, both species are little known beyond the circles of avid gardeners...
These fruits contain the poison egosaponin. When the fruit is crushed, its poison can stun fish if sprinkled on a pool of water. In the Orient, it is used as part of a traditional fishgathering technique." 
"As one might expect with any widely distributed species, Styrax japonicus is quite variable. Prior to recent collections, most plants in cultivation in this country came from a few individuals introduced at the turn of the century and therefore represented only a narrow slice of the potential genetic diversity of the species. Newly introduced populations from Korea may, in time, result in improved winter hardiness, stress tolerance, disease resistance, overall form, and landscape characteristics, thus increasing the adaptability of this attractive landscape tree." 
 Sup, K. M., Hyun, K. S., Ho, S. J., Yun, K. H., Hyeusoo, K., & Soo, C. Y. (2015). Honeybee Visiting and Floral Nectar Characteristics of Styrax japonicus Sieb. & Zucc. Journal of Apiculture, 30(1), 13-20.
 Arbore, A., & edici, P.D. (2006). The Snowbells of Korea Paul Meyer.