STRUCTURE OF WHEAT 



31 



the slits which are formed in the upper end of the two com- 

 partments. This process takes place apparently in a very short 

 space of time. (49) The ovulary is one-seeded and is sur- 

 mounted by two featheiy stigmas which prior to the opening ot 

 the flower are erect and adjacent. As the flower opens the 

 stigmas fall apart to receive the pollen. 

 Pollination being effected, the stigmas soon 

 wither and the ovulary rapidly enlarges. 

 The development of the ovule (seed) from 

 the period of flowering to maturity is very 

 rapid and emphasizes the importance of 

 proper soil and climatic conditions at that 

 time. (49) 



57. The True Flower. — The ovular}^ 

 stigma and stamens are enclosed within 

 two chaffy parts, the inner of which is called 

 a palea and the outer and lower the 

 flowering glume. These parts collectively 

 constitute the flower of the wheat. The 

 .awn or beard is borne on the flowering 

 glume and varies greatly in length in differ- 

 ent varieties or even in the same spike, or 

 may be entirely wanting. In some varieties 

 the awns are deciduous or partly so upon 

 ripening. They vary in color from very 

 light yellow to black. 



Organs of reproduction 

 in wheat : a, ovulary ; 



b, styles and stigmas ; 



c, anthers ; d, filannents 

 of stamens. Upper 

 left illustration shows 

 flower before opening ; 

 upper right illustration 

 shows flower about to 

 open and protrude an 

 thers. (After Hays,) 



58. The Spikelet. — Two to five flowers are enclosed within 

 two chaffy and still harder parts called empty or outer glumes. 

 This is called collectively a spikelet. There is considerable 

 variation in the number of flowers maturing seed, due to variety 

 and environment. In the varieties of common wheat there are 

 generally three or more flowers in each spikelet, which usually 

 matures two or three grains, — more commonly two. The outer 

 glumes differ from those in r)-e by being oval rather than awl- 



