HOW TO KNOW THE GRASSES 



Figure 355 



2b. Staminate spikelets in a "tassel" at the stem tips; pistillate spike- 

 lets on a many-rowed axillary "cob," surrounded by leafy husks. 

 Fig. 355. 



MAIZE; INDIAN CORN Zea mays L. 



Annual; tufted; plants 

 exceedingly variable in 



^^^^ \\W/ ^^^® °^^ habit, but char- 



v'/>r>C'\ \Y acteristically with thick, 



solid stalks. The pistil- 

 late inflorescence (ear) 

 has paired rows of spike- 

 lets. The glumes, sterile 

 and fertile lemmas form 

 the "chaff" that remains 

 on the cob. In a few va- 

 rieties, such as Country 

 Gentlemen, both florets 

 of each pistillate spikelet 

 develop grains, produc- 

 ing very crowded and ir- 

 regular rows. Corn is unusual in having united 

 styles, which form the "silk." The staminate in- 

 florescence (tassel), is much-branched and bears 

 pairs of spikelets, one of each pair being sessile 

 and the other pedicellate. Because of the great 

 crowding of the staminate spikelets, the arrange- 

 ment may be obscured. The staminate spikelets 

 are each two-flowered. 



Corn never persists after cultivation and is un- 

 known in the wild state. It is suspected that it 

 originated in Central America. 



Euchlaena mexicana Schrad. (TEOSINTE) is in- 

 termediate between corn and Tripsacum in struc- 

 ture. The staminate spikelets are borne in a termi- 

 nal tassel, like those of com, and the general ap- 

 pearance of the plants is like that of com. The 

 pistillate spikelets are borne in single spikes of 

 hardened joints, like those of Tripsacum. These 

 spikes break up into 1-spikelet segments when ripe. 

 They are hidden, however, in husks hke those of 

 the com ear. Teosinte is sometimes cultivated as 

 a forage plant in the South and occurs as a weed 

 in the American tropics. It is closely related to 

 com and hybridizes with it. 



185 



Figure 356 



