Characteristics of vegetative propagation of common comfrey (Symphytum officinale) as a weed in crop fields
Nemoto, M.; Shibuya, K.; Saigusa, M.
Weed Research Tokyo 40(3): 203-208
In the past, common comfrey (Symphytum officinale) was cultivated extensively in Japan for medicinal use, as well as for use as a vegetable and feed of domestic animals in the 1960s. In recent years, however, due to the reduced demand for common comfrey production, the plant has tended to remain in crop fields and to behave like a weed. In a study of one field, it was noted that individuals of common comfrey which exhibited various sizes and growing stages formed a dominant population.