CHAPTER VIII. — STRUCTURE OF THE FLOWER. 



6 7 



" double " flowers are flowers in which the petals or sepals are 

 multiplied beyond the normal number, as in the cultivated Rose, 

 the Camellia, and the garden Ranunculus. In the Cactuses, the 

 stamens, and in the wild Buttercups, the pistils, are very numer- 

 ous. Sometimes the multiplication of parts takes place by the 

 formation of new whorls, and sometimes by an increase in the 

 number of parts of the same whorl. 



Both incompleteness and redundancy tend more or less to 

 obscure the numerical plan, but usually it may still be discerned 

 in one or more of the whorls. 



Fig. 204. — FloTrer of Aconite : a, as it appears when faliy expanded ; c, with the parts 

 separated, showing the hooded upper sepal, the two large lateral sepals and the two smaller 

 ones ; underneath the hood are the two petals. 



(3) Deviations due to the Anteposition of parts. Normally, 

 as has been stated, the whorls alternate, but occasionally they 

 are anteposed, or have the pieces of successive whorls placed 

 one in front of the other. In the Barberry and the Blue Cohosh, 

 for example, the stamens come opposite to the petals, and in the 

 Iris the stigmas (which are the upper part of the pistil) come 

 opposite the stamens. 



(4) Deviations due to the Irregularity of Parts. Irregularity 

 in the size, shape or coloring of parts, particularly of the calyx 

 and corolla, are very common. In the Figwort and Mint families 



