Comfrey (also comphrey) is a common name for plants in the genus Symphytum. Comfrey species are important herbs in organic gardening. It is used as a fertilizer and as an herbal medicine. The most commonly used species is Russian comfrey Symphytum × uplandicum, which is a cross or hybrid of Symphytum officinale (common comfrey) and Symphytum asperum (rough comfrey).
Comfrey (Symphytum officinale L.) is a perennial herb of the family Boraginaceae with a black, turnip-like root and large, hairy broad leaves that bears small bell-shaped flowers of various colours, typically cream or purplish, which may be striped. It is native to Europe, growing in damp, grassy places, and is locally frequent throughout Ireland and Britain on river banks and ditches. More common is the hybrid between S. officinale and S. asperum, Symphytum × uplandicum, known as Russian Comfrey, which is widespread in the British Isles, and which interbreeds with S. officinale. Compared to S. officinale, S. × uplandicum is generally more bristly and has flowers which tend to be more blue or violet.
Comfrey has long been recognized by both organic gardeners and herbalists for its great usefulness and versatility; of particular interest is the "Bocking 14" cultivar of Russian Comfrey. This strain was developed during the 1950s by Lawrence D Hills, the founder of the Henry Doubleday Research Association (the organic gardening organisation itself named after the Quaker pioneer who first introduced Russian Comfrey into Britain in the nineteenth century) following trials at Bocking, near Braintree, the original home of the organization.