CH. XII] DOG-DAISY. 163 



only half grown while the anthers (A) are mature and 

 project from the mouth of the corolla; in the older flowers 

 the anthers having played their part wither and fall from 

 the filaments, while the styles, having become mature and 

 capable of pollination, have grown so that they project 

 at the mouth of the corolla and occupy the position of the 

 stamens in the younger flower. 



Dog-daisy (Chrysanthemum leucanthemum). 



What is ordinarily called the flower of the daisy is in 

 reality an inflorescence, a number of minute flowers 

 massed together on a button-shaped stalk 1 . The white 

 rays springing from the edge are not petals, as they are so 

 often called, but each is a minute flower or floret, and the 

 same thing is true of the minute round-headed pegs which 

 make up the yellow mosaic-work in the centre of the 

 flower-head. We have in fact a state of things essentially 

 the same as that in the plantain, the shape of the axis on 

 which the florets grow being the only point of difference 

 between the two forms of inflorescence. In the dog-daisy 

 the flower-head is surrounded by a number of green scales 

 (bracts) which help the deceptive likeness of the head to a 

 flower, by resembling a calyx. 



In the daisy the yellow florets which make up the 

 centre of the head are known as disc-florets ; each has a 

 minute tubular corolla edged with five small teeth indi- 

 cating the five coherent petals. A floret of this kind from 

 a Senecio (a species allied to the common groundsel) is 

 shown in fig. 74, A. In fig. 74, C is shown a floret in 



1 The expanded axis on which the florets grow is called the receptacle. 



112 



