Pokeweed: Is It Poisonous?

I am trying to find out more about pokeweed. Does it have any useful properties? I have found that it is a cathartic poison but not sure if this full meaning. Can you explain this meaning further?

Yes, it does have useful properties. The roots are known to reduce inflammation and pain, to stimulate the immune and lymphatic systems, and to clear toxins. It has been recommended for autoimmune disorders, tonsilitis, mumps, swollen glands, and skin diseases. A saponin, phytolaccagenin, is a powerful molluscicide and parasiticide.
It has been most commonly used as a laxative – i.e., as a cathartic – but its effect is of long duration, up to 48 hours, and it can cause vomiting, and even have narcotic effects. Fatal overdoses have been recorded, and the plant contains a mitogenic substance that can cause blood cell abnormalities.
The American Herbal Products Association's Botanical Safety Handbook classes pokeroot as a herb that should be used only under the supervision of a qualified practitioner. In Canada, it cannot be sold in herbal products. In the U.S.A., the FDA considers it a herb of "undefined safety."
Michael Tierra says that the daily limit should 1 gram per day, but James Duke questions this, believing it to be too high.