Licenciado En Biologia

Manioc—A Tropical Staff of Life
A plant which in one form contains deadly prussic acid and in other forms nourishes thousands of primitive people and furnishes tapioca to modern man.

ROBERT W. SCHERY
Missouri Botgnieal Garden

Importance, Preparation, Use

PERHAPS it's a grain? No. A potato or bean? Certainly not. Well then, what other form of vegetable life may be so linked with man'sdaily existence as to be termed a "staff-of-life", to bear the burden of furnishing the basic food in the diet of many millions of men? Dwellers in the tropics—in the Americas from Mexico south to Paraguay— many of whom would scarcely recognize a potato and whose only acquaintanceship with important cereal grains is an occasional planting of maize, can tell you. It is manioc, the tuberous root ofManihot escidenta Crantz (M. uótilissima Pohl.) . Yes, manioc, or mandioc, or cas yuca, or any of several other -sav,or Indian- or Spanish-sounding titles, is the name of the most important—and frequently the only—primary source of sustenance to thousands of interior-dwelling Latin Americans and to their tropical brethren of even more distant lands. Surprising this may seem to North Americans. formost of us have never seen manioc nor even become familiar with its name, and little detail concerning it has been published north of the Spanishspeaking republics. Yet, unknowingly,. most of us have eaten it, in a specially prepared form, as tapioca. Amongst the Latin countries to our south manioc is known in an endless selection of varieties, many of which are poisonous to varying degree, forthe manioc species contains a poisonous glucoside

relatéd to prussic acid. Selection of "sweeter" varieties, those graced with less of the toxic glucoside, permits of more ready preparation than do the "bitter" maniocs, although I know of none that is not cooked or otherwise made edible by nan's hand. No hard and fast boundary exists. between "sweet" and "bitter" maniocs, all stages ofintermediacy being found. Quite probably growing conditions— soils, rainfall, elevation, and the like— are as important in determining the poisonous character of a, manioc as are the vague hereditary factors of varietal differentiation, or even more so. Basically two methods are followed to make palatable this essentially non-edible raw root. The simplest—one often used for sweet maniocs—consists of mereboiling in water as we might boil potatoes or sweet corn. Such boiling drives off or changes to inocuous form the small quantities of prussic acid or glucosidal poisons, just as would fermentation or extraction by mechanical means. A sticky, starchy, fibrous vegetable results, with á consistency as "heavy" as incompletely cooked macaroni. It retains its natural shape, much that of a very slendersweet potato. As such it is consumed, a staple item of the diet in outlying areas of southern Brazil, Paraguay and the Andean countries northward. But in northern and eastern Brazil, as perhaps elsewhere, the second and more elaborate mode of treatment gives
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MANIOC—A TROPICAL STAFF OF LIFE

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a readily handled staple, sacked and sohl much as is our wheat flour. There "farinha",' thefinal pulverized form of manioc, is the cheapest, omnipresent, and frequently the sole food for scores upon scores of native people+—peoples generally inadequately fed, to be sure, from the dietary standpoint. I have encoun-

roots in primitive local "mills". A horse or oxen yoked to a rotating beam continuously circles the hand-fashioned wooden gear, supplying power. A series of gears orpulley-belts ultimately rotates a wooden roller at high speed. Studs of nails, driven firmly into the roller on variowi planes, whir threateningly as an

Fic. 1. Young plants of manioc or cassava, Manihot esculenta, the source of farinha and tapioca and used industrially in laundry and sizing starches, adhesives, simple sugars, syrup, alcohol, acetone and animal fodder. (Courte.,sy of the New York...