254 



PLANT LIFE. 



may be lifted on a common tube with the calyx from which 



» ^- . it then seems to arise ; or it may be raised 



with the stamens, which then seem to be 

 attached to it, as in figure 267 ; or stamens, 

 corolla, and calyx may be lifted together 

 (figs. 288, 355). The corolla is ordinarily 

 not persistent, usually falling or withering 

 shortly after the microspores have been 

 lodged upon the stigma. 



357. Irregularity. — Both corolla and 

 274— Outline of a calyx are often radially symmetrical — i. e., 



r~JU oi Lychnis, 



showing long stalk the parts surrounding the center of the 



and an outgrowth, «, # 



the Hguie. Compare stem are of equal size and like shape, 



sen. and may be divided into several like halves 



by radial planes (figs. 275, 276). But often the symmetry 



of the calyx, and still more frequently that of the corolla, 



Fig. 

 petal 



Fig. 275. 



Fig 276. 



Fig. 275.— A flower of the flax, halved ; showing radial symmetry. See fig. 276. Magni- 

 fied 2 diam. — After Bessey. 



Fig. 276. — Diagram showing the arrangement of the parts of a flower of flax. Outer 

 circle, 5 sepals ; second, 5 petals ; third, 5 stamens; fourth, 5 carpels, each divided by a 

 false partition into 2 chambers. Five different radial planes will, therefore, divide this 

 flower into halves.— After Bessey. 



is so altered by unequal growth of the parts that the flower 

 can be divided into like halves by only one, or at most two, 



