2o6 BOTANY OF CROP PLANTS 



Beriberi. — This is a disease resulting from a diet consisting chiefly of 

 polished rice. Asiatic laborers who have been fed upon polished rice develop 

 this disease, while, if the rice is not polished, the disease does not appear. 

 When rice is polished, there is removed a large proportion of the phosphates of 

 the grain, and hence, when rice is almost the sole food, there is a deficiency 

 of phosphates in the ration, which lack results in the disease, beriberi. Of 

 course, those who have a mixed diet get the requisite amount of phosphates 

 from a number of different foods, and hence may eat polished rice without any 

 ill effects. 



Varieties. — Carleton gives the following provisional ar- 

 rangement of wild and cultivated rices: 



1 . Oryza granulata (wild rice) . 



2. Oryza officinalis (wild rice). 



3. Oryza sativa (cultivated rice). 



(a) utilissima. 



1. communis (large-kerneled rice). 



2. minuta (small-kerneled rice). 



(b) glutinosa (glutinous rice). 



American varieties are comparatively few in number. 

 Three main types are grown: Honduras, Carolina and Japan. 

 The hulls of Honduras and Japan rice are yellowish-brown, 

 those of Carolina rice mostly a golden yellow. Lowland 

 types of rice form, almost exclusively, the sorts grown in 

 this country. Japan rice has smaller grains, a thinner hull, 

 and tillers more than the other types in the United States. 

 Honduras and Carolina belong to the communis group, and 

 Japan to the minuta group. 



Distribution and Closely Related Species. — There is/ 

 is a great number of Oryza species found growing wild in 

 tropical regions of both hemispheres. The native home 

 of .0. sativa is the warm parts of Asia and Africa. Culti- 

 vated rice probably originated in eastern Asia. 



In this country, there are two quite common native 

 plants termed "rice." These are, Canada rice {Zizania 



