176 



STRUCTURAL BOTANY 



(Figs. 76 and 77, cp). The carpels are alternate with 

 the inner whorl of stamens, and are therefore opposite 



the outer stamens. During 

 the development of the 

 floral leaves, the stalk, on 

 which the whole flower-bud 

 is borne, goes on growing. 

 We see, then, the extreme 

 regularity and simplicity of 

 the Lily flower. All the 

 whorls consist of three 

 members each, they arise 

 in regular succession, and 

 the members of each 

 whorl always alternate 

 with those of the whorl 

 next outside them. The 

 diagram (Fig. 78), repre- 

 senting a ground-plan of the flower, illustrates this 

 regularity. 



b. Structure of the Perianth and Stamens 



The calyx and corolla are much alike in structure. 

 Both closely resemble foliage-leaves, but are some- 

 what simpler. The same systems of tissue, vascular 

 bundles, mesophyll, and epidermis, are present, and the 

 epidermis possesses stomata. The mesophyll, how- 

 ever, is destitute of chlorophyll granules, and in the 

 White Lily has no colouring matter at alL In the 

 yellow Lilies, such as the Tiger Lily, chloroplastids 

 are present, and where we get a distinctly red tint, as 



FIG. 78. Floral diagram of a 

 Lily, a, axis of inflorescence ; 

 b, bract ; s, sepals ; p, petals. 

 Within this are seen the two 

 whorls of stamens, and in the 

 middle the three carpels united 

 to form the ovary with axile 

 placentation. (After Eichler. ) 



