34 



SOUTHERN FIELD CROPS 



37. Leaves. — The leaves of wheat vary in width, and 

 even in the shade of green. As a rule, they are narrower 



than the leaves of barley and 

 oats. Young wheat plants of 

 the species usually cultivated in 

 the United States {Triticum 

 sativum) may be distinguished 

 easily from those of the other 

 small grains by the two small 

 clasps (auricles) that partly en- 

 circle the stem where the blade, 

 or free part of each leaf, imites 

 with the sheath (Fig. 12). In 

 the young wheat plant these 

 clasps bear on their margins a 

 Showing clasps bordered with few Very inconspicuous hairs. 

 No hairs occur on the larger 

 clasps of barley nor on the smaller auricles of rye. Oats 

 have no auricles. 



Fig. 12. — Part of a Young 

 Wheat Plant. 



hairs. 



Young plants of the four small grains, therefore, may be dis- 

 tinguished by the following leaf characters, as well as by others^ — 



Oats have no auricles or clasps (Fig. 1). 



Rye has very small auricles (Fig. 23). 



Barley leaves are provided with large auricles (Fig. 28). 



Wheat has auricles intermediate in size between those of rye 

 and barley, and on the outer margin of each auricle on American 

 wheats are a few hairs (Fig. 12). 



38. Pollination. — Although wanting in showy colors, the 

 part from which each wheat grain develops is a true flower. 

 On carefully opening the husk-like inclosing parts in a newly 

 formed head of wheat, within each flower are found three 



