WHEAT 



35 



Fig. 13. — Flobet of 



Wheat. 

 Showing two stigmas and 

 two of the three anthers. 



stamens, which soon afford the yellow powder or pollen. 



There is also a pair of small glistening plumes (Fig. 13), 



corresponding to the silks in corn. T\ 



These are the stigmas or divisions 



of the pistil, and in these deUcate 



plumes the pollen must lodge and 



grow before a seed can form. 



The plume-like stigmas are 

 snugly inclosed by the chaff, thus 

 preventing the access of any pollen 

 except that which develops within 

 the same flower. Hence wheat is a 

 self-poUinated plant. Therefore, 

 two varieties of wheat sown side 

 by side do not cross or mix, unless the seed be mechanically 

 mixed by careless handling. 



Two varieties of wheat can be crossed or hybridized by 

 removing the pollen-cases (anthers) before they burst, and 

 then, a httle later, by applying to the stigmas pollen 

 from a plant on which the anthers have just set free 

 the pollen. The best time for hybridizing wheat is before 

 daybreak. 



39. The spike and the spikelets. — " Spike " is the name 

 given to the entire head of wheat, and spikelet is the name 

 of a group of flowers or grains springing from the same 

 place on the stem. The head or spike is borne at the top 

 of each completely developed stem or straw. In wheat 

 there is only one spikelet, or flower-cluster, at each node or 

 joint. The spikelets are arranged alternately on the zigzag 

 stem (or rachis) . The spikelets are arranged flatwise to the 

 stem. 



