DO NOT TRY THIS AT HOME.
I have been pondering about this plant for sometime. Is there any reference to any Ancient European, or any hunter gatherer tride ever eating the tuber.
Could the tuber have been prepared like the Checky yam?
Plants for a future- Black bryony contains Saponins (can be used to stupefy fish) that are poorly absorbed by the body, and tend to pass through. They are also broken down through cooking.
The main toxic effect is by Calcium oxalate, found mainly in the fruit. Some web searches have said it is also contained in the tuber.
Some contradictions have arisen for Calcium oxalate. Some say it is destroyed when cooked or dryed. Others say it is not destroyed- but only in reference to fish, ie Mackeral.
Calcium oxalate is found in many a food source, including Spinach,Carrots even Hawthorn leaves.
I am not suggesting anyone go out and try, probably to toxic to prepare in any manner.
But who knows, it may have been used. Any ideas.
Regards Sparrow.