Abstract only availableThe American elderberry (Sambucus nigra L. subsp. canadensis R. Bolli) is an attractive shrub native to central and eastern North America that produces edible flowers and berries. In Europe, tea made from flowers of the subspecies nigra is a popular herbal treatment for respiratory infections such as colds and influenza. Potential active compounds in elderberry include phenolics such as quercetin, rutin, and chlorogenic acid. Very little is known about genetic, environmental, and seasonal influences on the concentration of such metabolites in the non-fruit tissues of elderberry, especially in the North American subspecies canadensis. The objective of this study, therefore, was to quantify the production of medicinal c...