Banned Herbs in Canada

I'm doing an essay for an herbalism course on "herbs not permitted in Canada". It seems to be a complicated subject, as some herbs are permitted to be grown, but their derivatives are banned (as with sanguinarine found in bloodroot ), and others (non-native) are banned entirely, as with kava kava, found in your catalog as the dried root. It makes sense to me that plants that are naturally growing in our midst can't effectively be banned, but I'm finding it difficult to find specific information. The government sites are not easy to navigate. I'm told there are approximately 9 herbs on a list somewhere, but that this tends to be revised and updated on a constant basis.
As a business that needs to be on top of the ever-changing rules on this I was wondering if you had any information to offer on the list of "banned herbs" in Canada?

This is indeed a complicated subject and I am not surprised that you are having trouble finding a list of banned herbs in Canada. Herbs are affected by a variety of laws and regulations. As a grower and seller of seeds, plants, dried herbs and herbal products, we are probably affected by more rules than most herbal companies. Not only are we affected by food and health laws we are also affected by agricultural and environmental laws because we sell seeds and plants too. We do not have a list of banned herbs precisely because herbs can be banned or restricted by a variety of mechanisms. Just as you described, a herb can be legal to grow and legal to use, but not legal to sell as a medicine, Or a herb can be legal to sell and use, but not to grow. Or a herb can be legal to sell if grown but not if gathered from the wild. The combinations and permutations are bewildering.
In our catalogue we indicate some herbs that we don't sell in Canada or ship to certain provinces. The dried kava kava and products based on kava kava are legal to sell in the United States but not in Canada. But if we had seeds or plants it would be legal to grow and use your own kava kava. Meanwhile a herb like scotch broom is legal to sell and use in Canada, but we don't ship seeds to British Columbia or Alberta because the plant is invasive in those provinces.
Even if we restrict your question to just dried herbs and products made from them it is still impossible to come up with a definitive list of what is not legal to sell in Canada. According to the natural health products regulations a herbal product can be approved for sale if for each component herb there is documentary evidence from the scientific or traditional literature that supports the claims made for the product. Trouble is the list of acceptable references is limited, and for practical purposes it is difficult to get approvals for many safe and effective herbs known to man. So in theory there are hundreds or even thousands of herbs that will never be approved for sale in Canada.