Asarum is a genus of prostrate woodland herbs with typically heart-shaped leaves and solitary 3-sepalled flowers arising at the nodes of long slender creeping rhizomes. Depending upon the taxonomic treatment and the generic circumscription, from 10 to 70 species may be recognized. Six species (as well as the ten species of the similar genus Hexastylis, included by some authors within Asarum) are native to North America. Asarum canadense, which is widely distributed in forests of the eastern United States, is frequently used as a shade-tolerant ornamental plant. European colonists used wild ginger as a culinary substitute for real ginger; Native Americans used it medicinally for a variety of conditions, including upper respiratory infections and gastrointestinal symptoms.

Wild ginger is related to the large, widespread genus Aristolochia (birthwort), which has also been used medicinally, especially in China, where it is sometimes used interchangeably with unrelated plants. These plants contain compounds called aristolochic acids, which have been described as ?anticancer compounds? based on in vitro studies. However, there is considerable evidence that in living animals and human beings, chronic consumption of aristolochic acid, perhaps especially when combined with certain pharmaceutical drugs, can cause a rare chronic kidney disease, permanent kidney failure, and even kidney cancer. All aristolochic acid-containing plants, including wild ginger, have been banned from commercial products. The amount of aristolochic acid in wild ginger is much smaller than that in Aristolochia species, and no illnesses associated with use have been reported; traditional uses probably posed very little risk. (Hexastylis may be much more toxic.) Nevertheless, since factors influencing individual susceptibility are not well understood, and plants of unquestionable safety with equivalent virtues are readily available, there is no reason to accept even a minute risk of serious harm. While wild ginger remains a lovely ornamental, it should no longer be recommended for human consumption.

Selected References

Debelle, F. D., J. L. Nortier, E. G. De Prez, C. H. Garbar, A. R. Vienne, I. J. Salmon, M. M. Deschodt-Lanckman, and J. L. Vanherweghem. 2002. Aristolochic acids induce chronic renal failure with interstitial fibrosis in salt-depleted rats. J. Am. Soc. Nephrol. 13:431-436.

Kelly, L. M. 1998. Phylogenetic relationships in Asarum (Aristolochiaceae) based on morphology and ITS sequences. Amer. J. Bot. 85:1454-1467.

Kelly, L. M. 2001. Taxonomy of Asarum section Asarum (Aristolochiaceae). Syst. Bot. 26:17-53.

Liu, M. C., S. Maruyama, M. Mizuno, Y. Morita, S. Hanaki, Y. Yuzawa, and S. Matsuo. 2003. The nephrotoxicity of Aristolochia manshuriensis in rats is attributable to its aristolochic acids. Clin. Exp. Nephrol. 7:186-194.

Nortier, J. L., M. C. Martinez, H. H. Schmeiser, V. M. Arit, C. A. Bieler, M. Petein, M. F. Depierreux, L. De Pauw, D. Abramowicz, P. Vereerstraeten, and J. L. Vanherweghem. 2000. Urothelial carcinoma associated with the use of a Chinese herb (Aristolochia fangchi). N. Engl. J. Med. 342:1686-1692.

Schaneberg, B. T., W. L. Applequist, and I. A. Khan. 2002. Determination of aristolochic acid I and II in North American species of Asarum and Aristolochia. Pharmazie 57:686-689.

Whittemore, A. L., M. R. Mesler, and K. L. Lu. 1997. Asarum. Pp. 50-53 in: Flora of North America Editorial Committee, eds. Flora of North America, vol. 3. Oxford University Press, New York.