30 



THE CEREALS IN AMERICA 



at least fift}'-two spikes have been produced from a single 

 seed. 



The " stand " of wheat may be materially affected by the 

 amount of tillering, and, therefore, a study of those conditions 

 which wall promote tillering is advisable. On the other hand, 

 it is probable that the best yields are not obtained where too 

 much tillering is encouraged through thin seeding. 



« In starting from the seed the stem soon begins to branch. The first leaves 

 which are sent up seem to be a temporary set of organs designed to quickly reach 

 above the soil, that the plant may be supplied with green cells in the sunlight. 

 These leaves form what appears to be the primary shoot of the plant, and spring 

 from the stem near the seed. They are found to be 

 dead in the spring, along with the germ whorl of 

 roots, in case of several varieties of winter wheat. 

 At the same point where these first leaves arise 

 another stem, apparently a rhizome, branches off 

 from the primary stem. This rhizome has an inter- 

 node quite unlike all the other lower intemodes, not 

 even covered by the sheath of a leaf, and extending 

 about half way to the surface of the soil. In case 

 the seed is planted two inches deep this rhizome is 

 about one inch long. At the top of this intemode 

 a joint bears a leaf, and a few other joints follow at 

 very short intervals, each having a bud in the axil of 

 its leaf." 2 



^mi 



A stool of wheat. 

 Culms are from a single seed 

 originally at a. One-third 

 natural size. 



56. The Organs of Reproduction. — 



The flower of the wheat plant has three 

 stamens. The anthers are attached to 

 the tapering end of the thread-like fila- 

 ments below the middle. As the flower 

 opens the filaments rapidly elongate, 

 pushing up and outside of the glumes the 

 anthers which previously were closely packed about the ovu- 

 lary.^ The attachment of the filament to the anther is such 

 that the anther suddenly upsets and the pollen falis out of 



1 Neb. Bui. 32, p. 91. 



2 Minn. Bui. 62 (1899), p. 407. 



S Note: The word o\Tilary is here used in its proper sense, instead «»f *he t^n* 

 uvary which Is so often inconectly used. 



