Black cohosh, Actaea racemosa L., is an understory perennial herb found in the mountains of Appalachia from Ontario to Georgia and as far west as Missouri and Indiana.  Though not as well known as other medicinal botanicals, such as American ginseng (Panax quinquefolius L.), and goldenseal (Hydrastis canadensis L.), black cohosh has a history and growing importance as a medicinal herb.  Used by Native Americas for a variety of conditions, current increasing demand for black cohosh is as a natural alternative for hormone therapy for menopausal women.  Though primarily wild harvested, the current supply in the wild and requirements for cultivation are largely unknown.  A proactive approach to sustainability is to determine information about plant habitat requirements and population dynamics to preventing the loss of populations through overharvesting.  Objectives of this study are to increase the potential sustainability of black cohosh through an understanding of habitat requirements for cultivation and an evaluation of the current availability, health and reproduction of the resource.   Known populations of black cohosh in western Maryland were analyzed for various environmental factors including site conditions and companion plants.  Based on known occurrences, Mahalanobis distance techniques were used to determine the potential location of additional populations.
Results/Conclusions

115 black cohosh populations were found in Potomac/Garrett State (PGSF), Savage River (SRSF) and in Green Ridge (GRSF) State Forests in western Maryland.  Importance values for overstory species were highest for sugar maple (Acer saccharum Marsh.), eastern hemlock (Tsuga canadensis (L.) Carrière), and American basswood (Tilia americana L.) at SRSF and PRSF.  GRSF had highest importance values for northern red oak (Quercus rubra L.), white oak (Quercus alba L.), and black cherry (Prunus serotina Ehrh.).  Soil samples had mean values of 4.66 for organic matter on a 1-5 scale with 60% on sandy loam soil texture.  Mahalanobis distance was calculated for populations and randomly selected locations.  73% of the observed locations were classified as ideal habitat.  Model testing using bootstrapping resulted in a predication accuracy of 82%.  Ideal habitat occurred on lower slopes, higher values of topographic convergence index, smaller “distance to stream” values and marginally higher pH than average.  Up to 30% of SRSF and PGSF are considered suitable habitat, while GRSF, with steeper drier slopes, has less than 10% suitable.  Characterization of important habitat variables will assist in sustainable management.  This information is applicable to related species facing declines, including Actaea rubifolia (Kearney) Kartesz and Actaea podocarpa DC.