AVENA 127 



the lower flower is the only one to bear an awn. The palet 

 is two-toothed, and shorter than the lemma. It fits closely 

 about the grain. Stamens three. Style branches two, plu- 

 mose. Lodicules two, very evident at flowering time. 



Opening of Flower and Pollination. — The inflorescence 

 opens at the tip first. In oats, as in other paniculate types 

 of inflorescences, there are a number of cells in the axils of 

 the primary branches which become turgid and bring about 

 the opening of the inflorescence. The first flowers to open 

 in the panicle are in the middle spikelets. The blooming of 

 the entire panicle is completed in six to seven days. In the 

 spikelet, the lower flower opens first, then the second and 

 third in order. The chief blooming time of oats is from 

 2 :oo to 4 :oo p.m. Blooming may continue at slackened speed 

 until 7:00 or 8:00 p.m. A flower usually remains open from 

 fifty to seventy minutes. Hence cross-pollination is not 

 excluded. Self-pollination is the rule, however, due to the 

 fact that all three anthers seldom project from the flower. 

 In cool or rainy weather, flowers may not open at all. 



Fertilization, and Maturing of Grain. — Oats and wheat are 

 very similar as to fertilization. . The oat grain passes through 

 the milk and waxy stages to maturity, as in wheat. After 

 the resorption of the outer integuments, resorption of the 

 parenchyma layer begins. There is a complete resorption 

 of the chlorophyll layer and the inner epidermis. There 

 seems to be a less marked fusion of pericarp and seed coats 

 than in wheat. 



The Mature Grain. — The kernel is firmly surrounded by 

 the lemma and palet, except in "naked oats." The lemma 

 and palet form the "hull" (Fig. 47). The quaUty of oats 

 is judged largely on the basis of per cent, hull and kernel. 

 Hull usually forms from 25 to 33 per cent, of grain weight, 

 but may be as low as 20 per cent, or as high as 45 per cent. 



