China and Japan
"Based on... chemical data, a systematic hypothesis was suggested that the complex S. japonica was originated in the southwest of China, and presented an evolutionary tendency from the west to the east." [1]
"The young leaves, fruits and roots of some of these plants have been used as diuretic, detoxicant and analgesic agents and also for the treatment of inflammation, cough, headache and toothache in traditional Chinese medicine." [1]
"There are more than 60 diterpene alkaloids and 7 diterpenoids isolated from Spiraea japonica, some of them were showed bioactivities of anti-inflammation, anti-platelet aggregation and neuroprotective effects." [1]
[1] Hao, X., Shen, Y., Li, L., & He, H. (2003). The chemistry and biochemistry of Spiraea japonica complex. Current medicinal chemistry, 10(21), 2253-2263.
