References
Angiosperm Phylogeny Group (APG). 1998. “An Ordinal Classification for the Families of Flowering Plants.” Annals of the Missouri Botanical Garden. 85(4): 531 – 553
Murray M., J. Pizzorno and L. Pizzorno 2005. The Encyclopedia of Healing Foods. 432-437.
Courter, J. W. and A. M. Rhodes, 1969. Historical notes on horseradish . Economic Botany 23.2 156-164
Davis, E. 2011. What is Horseradish? International Horseradish Festival
Gaertn, C., A. Mey, and A. Sherb 2010. Armoracia rusticana Horseradish PFAF Plant Database
Angiosperm Phylogeny Group (APG). 1998. “An Ordinal Classification for the Families of Flowering Plants.” Annals of the Missouri Botanical Garden. 85(4): 531 – 553
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 2: 163.
+ see pictures for their own sources