Herbalism - Symphytum officinale L. (Comfrey) roots -

NOTES:

comfrey (Symphytum officinale L.) roots contain the liver toxic lycopsamine

Essential oils do not contain alkaloids.  Alkaoids however find medical uses in herbalism.

alkaloid
Lycopsamine

http://en.wikipedia.org/wiki/Alkaloid

 http://en.wikipedia.org/wiki/List_of_psychoactive_plants

 http://en.wikipedia.org/wiki/Medical_cannabis

 http://en.wikipedia.org/wiki/50_Fundamental_Herbs#50_Fundamental_herbs

Ian Brealey