24 BULLETIN 468, U. S. DEPARTMENT OF AGRICULTURE. 
foods in Porto Rico, Hawaii, and the Philippines, ranking in Porto 
Rico, for instance, next to the sweet potato in importance. 
In appearance tubers of comparable size look much like sweet pota- 
toes, while in flavor and in composition yams very closely resemble 
potatoes. (See p. 27.) They have not, however, the keeping 
qualities of sweet potatoes, and in countries where they grow 
are usually left in the ground until required for use. Experience 
and experiment alike show that yams can be readily prepared in 
acceptable ways and are to be regarded as an important carbohydrate 
food in regions where they are available. The} 7 are prepared for the 
table in much the same way as potatoes and sweet potatoes. 
Starch is made from the yam and also a flour used in tropical coun- 
tries as a breadstuff. Like the flours and starches prepared from 
other edible roots, these yam products are not used alone for making 
yeast-raised bread, since they do not contain the gluten which is 
characteristic of wheat flour and which gives the light, porous texture 
to wheat bread. According to experimental evidence, 96 per cent of 
the carbohydrates present in yams is assimilated on an average. 
DASHEEN, TARO, AND YAUTIA. 
Dasheen, taro, and yautia are closely related botanically and are 
so much alike in general character and the uses to which they are 
put that they may be grouped together for discussion. They belong 
botanically to the Arum family, which includes also the large-leafed 
ornamental plant called Caladium or " elephant's ear," frequently 
seen in gardens, as well as the calla lily and the Indian turnip or 
jack-in-the-pulpit. Another member of the Arum family worthy of 
mention is the tuckahoe or Virgina wake-robin (Pentandra vir- 
ginica) , which is closely allied to the tropical America yautia. The 
tuckahoe grows in marshy bottoms and river banks. Its roots, like 
those of the yautia and Indian turnip, are very acrid when raw and 
are full of needles of oxalate of lime, but when cooked are of a very 
gocd flavor and much like the other aroid roots. The American 
Indians are said to have made a kind of bread of the tuckahoe, and, 
as the earlier records show, tuckahoe was of considerable importance 
to the pioneer settlers of the United States. 
The dasheen, taro, and yautia all form large underground root- 
stocks or corms, in which starch is stored, and the} 7 are important 
food plants in many tropical and subtropical countries. Taro is 
an important crop in Hawaii and, indeed throughout Polynesia, 
and from it the Hawaiians make the cooked and slightly fer- 
mented paste called poi, a characteristic and very important article 
of their diet. Taro, dasheen, and especially perhaps yautia, are 
common in Porto Rico, and it was largely through the experiment 
