MAY DEM 161 



202. Zea L. — Indian corn, maize. This genus is 

 represented only by the cultivated maize {Z. mays L.), 

 and is not known in the wild state. There are several 

 well-marked varieties, such as dent, pop and sweet, which 

 are thought by some to be distinct species. Like the pre- 

 ceding genus, the staminate inflorescence is separate from 

 the pistillate. The former is a terminal panicle called the 

 tassel and the latter, a thick spike surrounded by leafy 

 bracts or husks, is called the ear. The staminate spikelets 

 are in pairs on the rachis, 1 sessile and the other pediceled, 

 each 2-flowered, the thin lemmas and paleas being shorter 

 than the firm glumes. The ear consists of several close 

 rows of pistillate spikelets upon a greatly thickened axis, 

 the cob. The spikelet consists of 2 glumes, a .sterile lemma 

 with a small palea, and a fertile lemma and palea. All 

 these bracts remain at the base of the mature grain as 

 coriaceous chaff on the cob. The numerous single styles 

 protrude from the ear and form the "silk." There is a 

 potential ear in every leaf-axil but usually only one de- 

 velops into a perfect ear. In one variety, called pod-corn, 

 each kernel is enveloped in the elongated floral bracts. 



There has been much speculation as to the origin of corn. Some 

 have thought that it has been developed from Teosinte, others that 

 the original wild form has become extinct. It is more likely that it is 

 a hybrid between Teosinte and an unknown or extinct species re- 

 sembhng pod-corn. (Collins "The Origin of Maize," Journ. Wash. 

 Acad. Sci. 2:520. 1912.) 



Corn has been cultivated from prehistoric times by 

 the early races of American aborigines, from Peru to 

 middle North America, and is now cultivated throughout 

 the world in warmer regions for food for man and do- 

 mestic animals. The chief varieties are dent, the common 

 commercial field variety, flint, formerly common in the 



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