Comfrey is one of 35 species of hairy-leafed, flowering plants in the
Boraginaceae family, which includes many well-known relatives such as
fiddlenecks, heliotrope, forget-me-nots and borage.
Although comfrey
itself is an attractive plant that produces colorful bell-shaped
flowers, some gardeners would argue that its persistence to either
invade or escape uncontained settings would constitute a weed.
For centuries, comfrey leaf has been regarded as a vegetable in Asia and
the root as a tonic in central and western Europe. While it was once
common to produce teas and tinctures from the herb, the use or sale of
comfrey products for internal use are now restricted in the US, Canada
and Germany due to a high concentration of multiple pyrrolizidine
alkaloids. Other compounds in comfrey, however, such as rosmarinic acid
and allantoin, make the herb suitable for topical applications to
counter inflammation and minor skin irritations.
