|Colt's foot in early spring|
To use or not to use...that is the question for colt's foot, comfrey, borage, and life root. These and related species contain variable amounts of pyrrolizidine alkaloids (PAs) which are toxic to the human liver in concentrated doses.
|Colt's foot in late spring|
Comfrey (Symphytum officinale) is a prolific wound healer in part because it contain's allantoin, a chemical that stimulates cell growth. Comfrey also contains PAs which has resulted in it's sale being banned in some countries including the U.S. It's a good thing the vulnerary effects can be safely obtained by topical application of the leaves in a poultice or salve.
|Comfrey in late spring|
|Life root has purple buds but golden flowers|
HERBALIST'S NOTE: Use other topical wound-healing herbs (see Making an Herbal Poultice) instead of comfrey when slow healing is desired or scar prevention is a priority.