CLASSIFICATION AND CHOICE OF FIELD CROPS 3 



three of uncertain origin, making the total number of cultivated 

 species 248.^ He classifies the species as follows: 



Old World New Work 



Cultivated for the underground parts .26 6 



Cultivated for the stems or leaves • • 57 8 

 Cultivated for the flowers or their 



envelopes 4 O 



Cultivated for their fruits . • • • S3 24 



Cultivated for their seeds .... 58 8 



Cryptogram cultivated for whole plant . o I 



198 47 



6. Classification. — No classification of the field crops of the 

 United States can be made that will be entirely satisfactory 

 and even if it could be made so, would not remain satisfactory, 

 on account of new uses to which plants are constantly being 

 put. The following classification will be used in this chapter, 

 viz., cereals, grasses, legumes, tubers, roots, sugar plants, fibers, 

 stimulants, medicinal and aromatic plants and miscellaneous 

 crops. The following table shows the total area devoted to 

 each of these classes of crops and their value as reported by 

 census of 1900 : 



Area and Value of Field Crops in 1899, in U. S. 



Area (acres) ^'alue of crops Value per acre 



184,994,588 ^1,484, 



Hay and forage 2 , . 61,691,166 487, 



Cereals 184,994,588 ^1,484,231,038 $ 8.0a 



' ' . " " ,125,685 7.93 



Legumes for the seeds 1,964,634 28,308,228 14-36 



Tubers 2,938,952 98,387,614 33.47 



Roots 537,447 19,876,200 36.9S 



Sugar plants .... 855,995 51,367,685 60.0X 



Fibers 26,401,660 390,879,985 ix.02 



Stimulants .... 1,101,483 56,993,003 51.74 



1 Origin of Cultivated Plants. By A. De Candolle, pp. 436-446. 



* Of the total area in hay and forage crops, 6.7 per cent was devoted to clover, 

 50.7 per cent to tame and cultivated grasses other than clover, 6.3 per cent to 

 grains cut green for hay, 5.1 per cent to forage crops, 3.4 per cent to alfalfa, 

 2.8 per cent to millet and Hungarian grasses and 25.1 per cent to wild, salt and 

 prairie grass. — Twelfth Census, Bui. 217. o. 14.. 



