POTATOES AND OTHEE STARCHY ROOTS AS EOOD. 23 
important articles of diet, and as they may be readily shipped in 
good condition and are known to be palatable and wholesome, it 
seems not unlikely that they may become important additions to the 
list of starchy vegetables commonly used in the United States. Most 
of them have two distinct uses in the diet ; that is, they are used much 
like bread, as a common source of carbohydrate food, and, like succu- 
lent vegetables, as accompaniments of meat or other dishes. 
CASSAVA. 
The cassava is an American plant widely used for food purposes 
throughout Central America, the West Indies, and the hot regions 
of South America, and now cultivated to a considerable extent in 
Florida, but as a cheap source of commercial starch, glucose, etc., 
and as a cattle food, rather than as a vegetable. There appear to be 
two principal varieties, the sweet cassava and the bitter cassava 
(which is poisonous unless specially prepared, owing to the prussic- 
acid compound present), but only the sweet is cultivated in the 
United States. Both varieties (but the bitter only after proper treat- 
ment) are eaten as a vegetable, boiled, baked, fried, or cooked in 
other ways, and by drying and grinding are made into a flour which 
forms the basis of various sorts of bread and biscuits. Thin, crisp 
cassava cakes are not uncommonly sold in the United States under 
a variety of trade names. 
Judged by the figures given in Table III, page, 27, the cassava is as 
rich in starch as the potato, and like it can be classed as a succulent 
carbohydrate food. The amount of protein and fat present is very 
small, while the mineral matters are not remarkable in any way* 
The culture and uses of cassava and related matters have been dis- 
cussed in a previous publication * of this department. 
Cassava starch in the form of tapioca is produced in large quan- 
tities in the Tropics from the bitter cassava and is prized as a palat- 
able and valuable food starch. It is a common article of commerce 
much used for making puddings and other dishes. 
YAMS. 
True yams, sometimes confused in name with sweet potatoes, belong 
to a group of tropical and semitropical climbing plants cultivated in a 
number of varieties and producing edible starch-yielding roots. All 
of the edible species are of Old World origin. These vary greatly 
in size, some being no larger than potatoes and others several feet in 
length and weighing 30 or more pounds. Yams are known in only 
a limited way in the United States, but are common and important 
1 U. S. Dept. Agr., Farmers' Bui. 16Y (1903), pp. 32. 
