Comfrey Plants: What Are the Differences?

Comfrey plants and their differences:

_{The main difference between the three varieties of Comfrey plants is the alkaloid content. Alkaloids are the main factor implicated in the liver toxicity research studies.}

_{Prickly Comfrey (Symphytum Asperrimum): Prickly Comfrey is a naturalized herb found in Humboldt County, Sacramento county, British Columbia, and the Northeastern USA. The herb was introduced from Southwestern Asia. It is high in Echimidine, one of the more potent alkaloids. It is not indicated to be used as fodder for animals or in humans.}

_{Common Comfrey (Symphytum Officinalis): Common Comfrey is said to have a more elongated leaf and makes its own seed. It is the best of the three to grow for medicinal purposes because it usually contains less toxic alkaloids.}

_{Russian Comfrey (Symphytum x Uplandicum): This is also sold as Blocking 14 Comfrey: It is a sterile cultivar of the Russian variety (Symphytum x Uplandicum). It will not self-seed and grows more rapidly than the Common Comfrey. Russian Comfrey is better for composting and animal feed but contains very high levels of Echimidine, one of the more potent alkaloids. It is the variety used in the research papers on liver toxicity. Cattle are not as sensitive to alkaloids as rats for instance.}

_{In all three plants, the root has more alkaloid content than the leaf and that is important when reading the label on Comfrey products.}

_References:

_{http://www.herballegacy.com}