228 BOTANY AND PHARMACOGNOSY. 



Horde urn sativum is an annual grass with the flowers in ter- 

 minal cylindrical spikes resembling wheat. The spikelets are ses- 

 sile, i-flowered, and usually in clusters of three on opposite sides 

 of the notched rachis. The empty glumes are long and narrow, 

 forming a kind of involucre around the spikelet. It is supposed 

 that Hordeum sativum is a cultivated form of H. spontaneum 

 growing in the countries between Asia Minor and other parts of 

 Western and Southwestern Asia. Three important varieties are 

 distinguished depending upon the number of rows of grains in 

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



Fig. 126. 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. 



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

 H. sativum hexastichon includes the plants having the grains 

 in six rows, these having been cultivated since prehistoric 

 times and now cultivated in Southern Europe. H. sativum vul- 

 gare includes the plants in which the- grains are in four irregular 

 rows, and these are cultivated in northern temperate regions. 

 The latter plant is cultivated in the United States and furnishes 

 the grain used in the preparation of malt (p. 575). 



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

 to Central Mexico. It is extensively cultivated in the United 

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

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



