Cassava goes by many names: arrowroot, manioc, tapioca, kassave, mandioca and yuca, but it's different from yucca, an inedible, ornamental plant [sources: USDA, Durand]. Whatever you call it, you should only eat it cooked, and only eat the root if it was peeled before cooking [source: China Daily].
As with taro, you can eat both the roots and leaves of the cassava plant. This native South American plant is easy to grow in humid climates, and the root is a good source of nutrients, which is why it's now cultivated across South America and parts of Africa. Cassava leaves are also edible when cooked. [source: O'Hair]
The toxic culprit in uncooked cassava is a group of compounds that turn into hydrogen cyanide in your body. Hydrogen cyanide interferes with your body's use of oxygen, basically causing you to drown without the trouble of being submerged [source: CDC].
To cook cassava roots properly, you should always peel them first and discard the peel. Then, you can fry them like you would potato chips or french fries. You can also boil the roots just like potatoes, but make sure that they're completely cooked through. If the cassava that you have seems bitter, you can grate and soak the roots before cooking. [source: O'Hair]
Cassava leaves don't require quite as much care, but you still need to cook them. Boiled thoroughly, they're safe to eat and taste similar to collards or other hardy dark, leafy greens [source: Kwok].