European elder (Sambucus nigra), also known as black elder and elderberry, is thought to be beneficial for the prevention and treatment of influenza and upper respiratory infections, though there is still debate as to which stage of infection it is most effective in and even what the exact mechanisms of action are that lend elderberry its anti-viral effects. American elder (Sambucus canadensis) is a fast-growing, deciduous North American shrub that can reach up to 12 feet with flowers and berries similar to S. nigra. Elder flower extracts are also used to treat…