SOME USEFUL PLANTS 325 



certain grasses known as cereals, and on account of this 

 and other facts the Grass family is the most important 

 family of plants from the economic point of view. Wheat 

 is the most highly prized of the grains on account of 

 its high food value, digestibility, and fitness for bread- 

 making. The United States is the leading wheat- and 

 corn-growing country, producing more than one-fourth of 

 the world's crop of the former grain and four-fifths of 

 the latter. 



Rice is extensively grown in South Carolina and the 

 Gulf States, but the world's principal supply comes from 

 Asia. It differs from the other cereals in requiring to be 

 cultivated on land that can be flooded during part of the 

 year. For this reason rice culture is often attended by 

 malaria. 



405. Leguminous Seeds. — The Pea family (ie^uwi^iosft) 

 comprises about seven thousand species, and many seeds 

 which form a considerable part of human food are derived 

 from this family. The ones most generally used in our 

 own country are peas and beans. Whether eaten in an 

 unripe condition or after becoming mature and dry, they 

 form a highly valuable source of proteid food. Peanuts 

 are the seeds of a leguminous plant largely grown in the 

 South Atlantic States and elsewhere. Our crop of these 

 is largely consumed at home, but also forms a consider- 

 able article of export. Other leguminous seeds much used 

 as articles of food in Europe and elsewhere, although not 

 as yet largely consumed in the United States, are broad 

 beans or Windsor beans, chick peas, and lentils. 



406. Other Seeds. — A great number of seeds which do 

 not come from plants of the Grass family or the Pea fam- 

 ily are used as human food. The most important tropical 



