FLOWERS 



127 



FIG. 104. Flower of 



lizard 1 s-tail, with no 



calyx or corolla 



After Bugler 



adjacent cycles; that is, each petal opposite a space between 

 two sepals, each stamen opposite a space between two petals, 

 and so on. Very often this alternate ar- 

 rangement of the members of successive 

 whorls is less evident because one or more 

 whorls have more numerous or fewer parts 

 than the others, as in the case of the butter- 

 cups and crowfoots (fig. 103), roses, and 

 many other familiar flowers. In many 

 cases, as in the knotgrass (fig. 125), only 

 one set of floral leaves occurs. Such flow- 

 ers are said to lack petals and are known as 

 apetalous. Some flowers, as those of the lizard' s-tail (fig. 1 04) 

 and the willow (fig. 105), 

 are wholly destitute of 

 calyx and corolla. 



117. Staminate flow- 

 ers and pistillate flowers. 

 Such flowers as are shown 

 in figures 101-104, con- 

 taining both stamens and 

 pistils, are said to be 

 bitexuaL 1 Those which 

 contain stamens but not 

 pistils or pistils but not 

 stamens, like those of the 

 willow (fig. 105), are said 

 to be unisexual. Many 

 families of dicotyledon- 

 ous trees and shrubs, 



Such as the Willow faill- A, stamiuate catkin, natural si/e ; R, pistillate 

 ilv thp Oak familv and Catkin, natural size ; C, stamiuate flower, mag- 



iiy, ti uak lamily, ana ^^ J} piHtmate flowert . magnified . After 



Others, have unisexual Cosson and De Saint-Pierre 



1 The flower itself is not sexual at all, as will appear later, but these 

 trrnis have come into general use, and their application to the two kinds of 

 flower seems likely to continue. 



FIG. 106. Dioecious flowers of 

 (Sato atba) 



"hite willow 



