THE DICOTYLEDONES 



1787 



and bears numerous bristles. Both Circaea lutetiana and C. alpina are 

 widely distributed in Europe and western Asia. In C lutetiana (Fig. 

 1679) the flowers are pollinated by hover flies. Two stamens project 

 one on each side of the pendulous flower and between them is the style 

 which projects rather further and bears a terminal knobbed stigma. Th«se 



Fig. 1679. — Circaea lute- 

 tiana. Flower in longi- 

 tudinal section. 



three structures serve as an alighting platform on which the insect must 

 support itself while reaching for the nectar, secreted from a ring at the base 

 of the style. Since the style is somewhat longer, most insects alight on it 

 first, and' it therefore receives the pollen from another flower, after which 

 the insect's body becomes dusted with pollen from the anthers as it forces 

 its way towards the nectar. Self-pollination is exceptional for it rarely 

 happens that the stigma comes into contact with a dehisced anther. 



MALVALES 



The Malvales are Archichlamydeae in which the flowers are bisexual, 

 regular, hypogynous, actinomorphic and pentamerous. Both the androe- 

 cium and gynoecium may show^ a great increase in the number of parts. 

 There are five sepals which are valvate in the bud and either free or united 

 in the mature flower. The petals are free and often imbricately twisted. The 

 stamens are arranged in two whorls, though those of the outer whorl may be 

 absent or replaced by staminodes. The inner whorl may be composed of 

 numerous stamens often with their fllaments united to form a column 

 around the style. The number of carpels is variable but they are united to 

 form a multilocular ovary, each loculus having one to many anatropous 



ovules. 



The order includes many trees and shrubs as well as herbaceous plants, 



