SECTION 8.] PLAN OF THE FLOWER. 83 



the petals stand over the intervals between the sepals ; the stamens, when 

 of the same number, stand over the intervals between the petals ; or when 

 twice as mauy, as in the Trillium, the outer set alternates with the petals, 

 and the inner set, alternating with the other, of course stands before the 

 petals; and the pistils alternate with these. This is just as it should be 011 

 the theory that the circles of the blossom answer to whorls of leaves, which 

 alternate in this way. While in such flowers the circles are to be regarded 

 as whorls, in others they are rather to be regarded as condensed spirals of 

 alternate leaves. But, however this may be, in the mind of a morphological 

 botanist, 



243. Flowers are altered Branches, and their parts, therefore, altered 

 leaves. That is, certain buds, which might have grown and lengthened 

 into a leafy branch, do, under other circumstances and to accomplish other 

 purposes, develop into blossoms. In these the axis remains short, nearly 

 as it is in the bud ; the leaves therefore remain close together in sets or 

 circles ; the outer ones, those of the calyx, generally partake more or less 

 of the character of foliage ; the next set are more delicate, and form the co- 

 rolla, while the rest, the stamens and pistils, appear under forms very dif- 

 ferent from those of ordinary leaves, and are concerned in the production 

 of seed. This view gives to Botany an interest which one who merely no- 

 tices the shape and counts the parts of blossoms, without understanding 

 their plan, has no conception of. 



244. That flowers answer to branches may be shown, first, from their 

 position. As explained in the section on Inflorescence, flowers arise from 

 the same places as branches, and from no other ; flower-buds, like leaf-buds, 

 appear either on the summit of a stem, that is, as a terminal bud, or in the 

 axil of a leaf, as an axillary bud. And, as the plan of a symmetrical flower 

 shows, the arrangement of the parts on their axis or receptacle is that ol 

 leaves upon the stem. 



245. That the sepals and petals are of the nature of leaves is evident 

 from their appearance ; they are commonly called the leaves of the flower. 

 The calyx is most generally green in color, and foliaceous (leaf-like) in 

 texture. And though the corolla is rarely green, yet neither are proper 

 leaves always green. In our wild Painted-cup, and in some scarlet Sages, 

 common in gardens, the leaves just under the flowers are of the brightest 

 red or scarlet, often much brighter-colored than the corolla itself. And 

 sometimes (as in many Cactuses, and in Carolina Allspice) there is such a 

 regular gradation from the last leaves of the plant (bracts or bractlets) into 

 the leaves of the calyx, that it is impossible to say where the one ends and 

 the other begins. If sepals are leaves, so also are petals ; for there is no 

 clearly fixed limit between them. Not only in the Carolina Allspice and 

 Cactus (Tig. 229), but in the Water-Lily (Fig. 228) and in a variety of 

 flowers with more than one row of petals, there is such a complete transi- 

 tion between calyx and corolla that no one can surely tell how many of the 

 leaves belong to the one and how many to the other. 



