196 PRACTICAL BOTANY 



a. Form of papilla, conical. 

 &. Apex becomes flattened. 



c. Periphery of the flattened apex rises into a whorl 

 of five small lobes ; these are the petals, which are in 

 the mature flower united as a gamopetalous corolla. 



d. Between the corolla and the now depressed apex 

 rises a fresh series or whorl of five lobes ; these are the 

 young stamens. 



About this stage may be seen externally, below the 

 corolla, a slight protuberance on each side of the flower 

 (as seen in section) : this is the first appearance of 

 the calyx, which consists in the mature flower of two 

 scaly sepals. 



N.B. This order of appearance of the floral whorls is not 

 normal, but is the rule in the order Compositce. In the large 

 majority of plants the calyx is developed first, then the corolla, 

 and then the stamens. 



e. Within the whorl of stamens there arises, at the 

 margin of the now much depressed apex, the last series 

 of floral organs, viz. two carpels, which arch over the 

 apical depression, and thus close in the cavity of the 

 inferior ovary. 



f. All the organs increase in size, while from the 

 base of the cavity of the ovary a papilla arises, which 

 develops into a single anatropous ovule, with one 

 integument, and small nucellus. (For the details 

 of development of the ovule, see CaltTia, p. 206.) 



II. Cut horizontal (i.e. transverse) sections of a capit- 

 ulum : treat as before : examine with a low power. 



Note the arrangement of bracteoles, with young 

 flowers in their axils, round the central naked apex. 



