308 FIELD CROPS 



the nodes or joints are always solid. This construction of 

 the stem allows the plant to stand considerable strain from 

 wind and rain without injury. The base of the leaf forms 

 a sheath around the stem, which further strengthens it; the 

 sheath is usually split to the base on the side opposite the 

 blade. A thin, hard ring, called the ligule, forms the junc- 

 tion of the blade and the sheath, clasping the stem or culm 

 and acting as a guard against the entrance of rain or dust to 

 the inside of the sheath. 



The flowers are borne in spikes or panicles, made up of 

 spikelets of two or more bracts or scales. They consist 

 of from one to three very small scales, from one to six 

 stamens, and a one-celled ovary, usually with two styles. 

 The flowers may, however, be imperfect, as in the case of 

 the tassel flowers of corn, which have no pistils. The stigmas 

 are hairy or plume-like, and the anthers are attached at or 

 near their middles to the filaments, so that they swing freely 

 in every breeze. The fruit is a caryopsis, the seed or grain 

 being enclosed in a membrane which adheres closely to it. 



381. Differences. The grasses, though they have many 

 characters in common, are quite variable. In height, they 

 vary from a few inches, as in the case of many of our native 

 prairie grasses, to several feet, as in corn and sorghum, while 

 some of the bamboos grow to the height of large trees. The 

 stems may be hollow, as in wheat or oats, or filled with pith, 

 as in corn. A large proportion of the leaves may be produced 

 at or near the base of the stem, making the grass valuable 

 for pasture, or many of the leaves may be borne on upright 

 stems, the plant then being suitable for hay. The flowers 

 may be perfect, as in wheat; monoecious, as in corn; or 

 dioecious, as in the buffalo grass of the western prairies. 

 They may be borne in close spikes, as in timothy; in loose 

 spikes, as in wheat or rye; or in panicles, as in oats or red- 



