Comfrey is traditionally known as knitbone or boneset with many uses both in the garden and medicinally.
The leaves make for great compost tea and mulching material as they are high in minerals and nitrogen. In permaculture, due to it’s deep tap root comfrey is known as a mineral accumulator and often planted under fruit trees as natural fertilizer.
Also the leaves can be used externally as a poultice to help repair a broken bone by promoting cell division.
Propagates easily from root cutting or crowns. Some cultivars are bred not to produce seed to control spreading of the plant.
Resources and more information:
How To Grow Comfrey: Care, Types & Growing Tips: https://happydiyhome.com/comfrey/