Comfrey - Symphytum officinale is a plant in the knit bone family. It is a superb healer of broken bones, sprains, tendon tears, bruises, swellings, sever cuts. The salve we make is the leaf infused in Olive oil, set up with beeswax. Simple and plain. Comfrey is know to have an analgesic property which helps reduce pain as it heals. NO Essential