82 CULTIVATION OF PLANTS. 



I. WHEAT. 



Of what country wheat is a native, is, according to LOUDON, 

 totally unknown. It has been supposed indigenous to Asia and 

 Africa; and unquestionably it is more likely to belong to these 

 parts of the world than any other; but all that can be advanced 

 on this subject is conjecture. 



Wheat, with the exception of some parts of the southern 

 coast of Africa, (where, according to the declaration of PLINY, 

 it yielded more than an hundred fold,) is cultivated in every 

 part of the temperate and torrid zones, and in some places as 

 high as two thousand feet above the level of the sea. 



Species and varieties. Botanists reckon seven species of 

 Triticum, which are or may be cultivated for their grains, be- 

 sides many varieties and sub-varieties of those in common cul- 

 ture. The species or sub-species are, 



1. Triticum aestivum, summer or spring wheat. 2. Triticum 

 hybernum, neuter or Lammas wheat. 3. Triticum composi- 

 tum, Egyptian wheat. 4. Triticum turgidum, Turgid wheat. 

 5. Triticum polonicum, Polish wheat. 6. Triticum spelta, 

 Spelta, Spelt wheat. 7. Triticum monococcum, one grained 

 wheat. 



The first, second, fourth and fifth sorts are by many consi- 

 dered as only varieties, and it is doubtful whether the third and 

 sixth may not be the same. The seventh has all the marks of 

 a distinct species, but it is very questionable whether, if much 

 cultivated, it would always continue to produce one row of 

 grains.* 



Of the species which have been enumerated, greatly the most 

 important in rural economy is the winter wheat. The kinds 

 of it are very numerous, and, in truth, there is scarce a limit 

 to the differences which climate, soil, and situation may pro- 

 duce. 



The characters which it thus acquires in the different condi- 

 tions in which it is placed, are more or less permanent and im- 

 portant. The kinds are distinguished by a great variety of 

 local terms, derived from their respective qualities, their places 

 of growth, and other circumstances. 



With respect to their uses in agriculture, they may be divided 

 into two classes, distinguished by the colour of their seeds, red 

 and white; and these may again be distinguished by their 

 spikelets being smooth or hairy, the one being termed thin or 

 smooth-chaffed, and the other thick or woolly-chaffed. 



Of these classes, the white are superior in the quality of their 



* Encyclopedia of Agriculture, p. 812. 



