[colorado tanker]

Description: A tough tropical plant grown for its fat starchy roots. The roots are boiled and eaten in soups and stews, or ground into flour and made into dumplings, puddings and breads, and used as a thickener for sauces and pies.

Fact: Scientists think the tiny amount of cyanide in prepared cassava may actually help people who eat it every day. It may protect them from diseases such as malaria and sickle cell anemia.

POISON NOTES: Cassava roots contain cyanide but can be made safe to eat by boiling or peeling, grating and washing repeatedly to remove the poison. The little bit of cyanide that remains may actually be beneficial.

Symptoms: Eating raw cassava can cause abdominal cramping, diarrhea and vomiting. High levels of cyanide prevent oxygen from getting into the blood and may even cause death.

[Vietnam Vet From New Mexico]

I have always wondered how humans ever discovered a way to treat manioc. You would thing that after seeing what happened to the first person to sample it, they would have left it alone.

[Sawdring]

If you trust the information in Wikipedia there is some interesting information under the Processing and Toxicity sub-heading.