CLASSIFICATION OF ANGIOSPERMS. 469 



the ear. H. sativum distichon includes the plants having 2-rowed 

 ears, and these are chiefly grown in Middle Europe and England. 

 H. sativum he.vasticJion includes the plants having the grains in 

 6 rows, these having been cultivated since prehistoric times and 

 furnishes the winter barley. H. sat wit in vulgar r includes the 

 plants in 'which the grains are in 6 irregular rows, and these 

 are cultivated in northern temperate regions. The latter plant 

 is cultivated in the United States and furnishes the spring or 

 summer barley, largely used in the preparation of malt. 



Zea Mays (Indian Corn) is a cereal plant probably indigenous 

 to Central Mexico. It is extensively cultivated in the United 



FIG 256. Diagrammatic outline of a spikelet: nY, lower glume; < Y, upper glume; 

 nl, outer pale; $ I, inner pale; 1, 1, lodicules; st, stamens; I-I, main axis; II, lateral axes 

 or branches. After Warming. 



States and other parts of the world for its grain. From a multi- 

 ple, primary, somewhat fibrous root arise one or more erect simple 

 culms, which are grooved on alternate sides in the successive 

 internodes and from the nodes of which arise aerial secondary 

 roots. The leaves are alternate and consist of 3 parts: (a) a 

 blade, which is long, broadly-linear and tapering toward the apex, 

 the tip being pendulous; (b) a lower sheathing portion which 

 is open; and (c) a short, translucent, somewhat hairy ligule, 

 situated between the sheath and the blade. The flowers are 

 monoecious, the staminate, which are arranged in a terminal pan- 

 icle, maturing first ; the pistillate occur in axillary spikes, the 

 axes of which constitute the corn cob. They are enclosed in- 



