Comfrey

Comfrey, Russian (Symphytum uplandica x)
high mineral content (deep tap roots).  Leaves high in B12 (many plants don’t)
roots & leaves can be harvested for various medicinal properties 
Superior healing properties for bone fractures, tendons, connective tissue, concussive traumas, bruising, inflammation, scar tissue, external wounds etc.  Delay applying to deep wounds (lacerations) because healing can be too rapid on top dermal layers initially
great for poultices
high protein 
Contains Allantoin (highest in roots - external use only) 
Leaves can be used internally for ulcers/damaged mucosal lining.  Leaves of Symphytum uplandica x (Russian Comfrey) are safe for internal use however Symphytum officinale (Common Comfrey) are not
must have herb for horse owners!  So many applications for a an animal that always seems to find trouble!
 
Perennial herb with pretty blue/purple flowers, growing up to 2m. Likes well drained, moist soil. Does best in part shade. Drought sensitive, frost tolerant but dies back over winter in cooler climates. Can be used for borders, mulch and a compost activator. Can be invasive if roots disturbed. Great in damp areas and can stabilise soil. Some horses may snatch small amounts, however it is not typically a favourite browsing herb. Best avoided by pregnant mares if they have a taste for it. 
 
Worth noting… MUCH confusion happens over Russian v Common Comfrey.  Majority of Comfrey sold these days is Russian (proper identification always required) and was hybridised during WW2 by Henry Doubleday to make it safe to consume the leaves.  Russian Comfrey was also bred to not produce seed (sterile).  Many herbalists still lump both in the ‘unsafe internally” boat however due to lack of official studies, many herbalists have sent S. uplandica leaves into labs and found NO or extremely low levels of Pyrrolizidine alkaloids present.  Roots of both varieties are NOT recommended for internal use.