Name: Manioc (Manihot esculenta)
Otherwise known as: Cassava, Tapioca Tree
Habitat: A shrub member of the Euphorbiaceae family, growing up to 3m in quite poor soil and native to Central and South America but now grown throughout the tropical world. It has thick, fleshy roots that support slender stems containing palmate leaves and produce racemes of white flowers that transform into the winged fruit capsules.
What does it do: Manioc is one of the main sources of carbohydrates and is the daily staple food for over half a billion human beings. The root contains deadly hydrocyanic acid and has been responsible for many fatalities and a debilitating neurological disease. To remove the toxin and render it edible, the root is steeped in water, drained and pressed when freshly harvested, then the water is drained off leaving the husk to be dried and sliced and ground into flour for bread or fried like fritters, or boiled and mashed.
In Third World countries it is a major cash crop because in addition to its food value it is a valued adhesive applied to stamps, envelopes, and a prime method for bonding plywood. An obvious advantage to poor communities is that it is drought resistant and can survive in barren soil without any nutrients. Over two hundred million tons are produced annually.
The plant yields any number of valuable chemicals once the toxin is eliminated such as amentoflavone, ascorbic and malic acid, quercetin and yucalexin. It is anti-microbial, anti-fungal, anti-bacterial and vermicidal. Native medicine men and women use the leaf and stem to repel intestinal worms and as a cure for diarrhea. In the western world processed manioc is prescribed for coeliacs and those with gluten allergies. Modern research has investigated whether the claims made for the plant being a treatment for topical tumours is valid. Manioc contains small quantities of Vitamin B17 that is known to be a bar for certain cancers.
Many post war scholars will recall manioc in its most popular form as the desert of choice on the school dinner menu – tapioca.
Alexander McCowan is author of The World’s most Dangerous Plants