GRASSES OF IOWA. 



Fig. 3. Different types of maize, o, Yellow dent; 6, vellow flint ; c. sweet corn; d, pop-corn. 

 (Photograph by Charlotte M. King.) 



The Zea canina of Watson 1 according to Sturtevant, is most closely- 

 allied to the pop-corn. Doctor Sturtevant has arranged cultivated corn 

 into the following groups: 



The pod-corn, Zea tunicata. Stur. Torr. Club. 1894: 335. 

 The pop-corn, Zea everta- Stur. Bull. Torr. Bot. Club. 1894: 324. 

 The flint-corn, Zea indurata. Stur. Bull. Torr. Bot Club. 1894: 327. 

 The dent corn, Zea indcntata. Stur. Bull. Torr. Bot- Club. 1894: 329. 



1 Proc. Am. Acal. Arts & Sci. 26: 158. Contr. Am. Bot. 18: 158. 



