Medicinal source:

Stryamets, N., Elbakidze, M., Ceuterick, M., Angelstam, P. & Axelsson, R. (2015). From Economic Survival to Recreation: Contemporary Uses of Wild Food and Medicine in Rural Sweden, Ukraine and NW Russia. Journal of Ethnopharmacology. 7 (1): 1-93. [MPNS is grateful to Patricia van Eijndthoven for providing the data from this reference.]