282 



TYPICAL FLOWERING PLANTS 



the clasping base. The corn leaf is long and narrow ; it 

 curves, and has wavy edges. Veins run from the base 



to the tip without branch- 

 ing, giving the parallel 

 venation characteristic 

 of the monocotyledons. 



A cross section of a 

 corn leaf shows that it 

 has the same structure 

 as the bean leaf. The 

 stomata are aided in pre- 

 venting undue transpira- 

 tion during dry, hot 

 weather by the tight 

 rolling of the leaf. 



215. Other Seedlings. 

 — All dicotyledonous 

 plants are like the bean 

 in having two cotyledons, but differ in other respects. 

 Peas, for instance, do not bring their cotyledons above 

 ground. Morning glories have their cotyledons folded in 

 the middle ; maple seed- 

 lings have theirs folded 

 on each other. Many 

 seedlings have leaves 

 which differ in shape 

 from those of the mature 

 plant (Figure 271). 



All monocotyledonous 

 plants are alike in hav- 

 ing only one cotyledon 

 which usually remains in 



the soil during germina- Figure 278. — Roots of Radish. 



tion. The first seed- Containing stored-up food. 



Figure 277. — Wheat Seedlings. 



a, grown in sunlight ; b, grown in 

 the dark. 



