174 FIELB CROPS FOB THE COTTON-BELT 



The date at which maize was first cultivated in Mexico 

 is not clear. Harshberger, as a result of his studies of 

 maize, concluded that it probably came into cultivation 

 in Mexico about the beginning of the Christian era, being 

 brought across the Rio Grande about 700 A. D. and reach- 

 ing the coast of Maine some time previous to the year 1000. 



In 1492, when Columbus discovered America, maize 

 was rather extensively cultivated by the T^erican In- 

 dians. After its discovery on the western hemisphere it 

 was rapidly introduced into Europe, Africa, China, and 

 Asia Minor. 



216. Biological origin. — Our present conclusions re- 

 garding the biological origin of maize are based largely 

 on a comparative study of the structure of maize and 

 its botanically related forms together with a consideration 

 of the embryonic development of the maize plant itself. 

 Maize belongs to the family GramineEe and to the tribe 

 Maydeae. The most important distinguishing featm-e of 

 the tribe Maydeae is the separation of the staminate flowers 

 from the pistillate flowers. Two grasses belonging to this 

 tribe and therefore closely related to maize are teosint© 

 (Euchlaena mexicana) and gama-grass {Tripsacum dacty- 

 loides) (Fig. 29). Both of these grasses are of common 

 occurrence in the high plateau region of central and south- 

 ern Mexico — the region in which corn is thought to have 

 originated. 



Teosinte is a coarse annual grass growing from 8 ,to 12 

 feet high, adapted to a rich soil and a long growing season 

 of moist hot weather. As a rule it does not mature seed 

 north of Mexico. Teosinte is a branched plant bearing 

 a terminal tassel on which only staminate flowers are 

 produced, and lateral branches from the axils of the leaves, 

 each bearing a terminal tassel on which only pistillate. 



