If your comfrey has purple/pink/lavender flowers and the leaves have ribs that continue down the stalk of the plants stem, This is a safe edible and medicinal plant. The comfrey that grows wild and has yellow flowers is a more potent version.
But i have read many herbalists accounts confirming that comfrey is safe for regular use. The tea is so delicious and sweet...like sweet cucumber.
Yes, mine has purple or pink flowers, so I'm safe... How do you make the tea? Just steep the leaves in boiling water? Dried leaves?
I used to sandwich a ramsons leaf in between two comfrey leaves in my fritters. It became known as "green fish"