Rich said: Calamus is harder to find. Ideally if it is more than for intermittent use you would look for A. calamus subsp. americanus, or sometimes simply called Acorus americanus as it is the safest onen for long term or frequent use. Not sure if you're looking for bulk herb? You can more easily find the other species and subspecies of it. I actually grow it and gather it myself so I do not have a good source per se. For tincture you could try RavenCrest Botanicals in upstate New York!