Goldenseal (Hydrastis canadensis L., Ranunculaceae) is a popular medicinal plant and has been listed in Appendix II of the Convention on International Trade in Endangered Species (CITES). The herbaceous perennial is distributed in North America under deciduous forest canopies throughout much of the south and eastern seaboard north into Canada. The rhizome, rootlets and root hairs produce medicinally active alkaloids. Although berberine, one of the Hydrastis alkaloids, has shown anti-fungal activity, the influence of Hydrastis alkaloids on the plant rhizosphere fungal ecology has not been...