CH. XII] SILENE. 161 



that of another flower. The particular form of dicho- 

 gamy in the plantain is known as protogyny 1 because the 

 gynoscium matures before the androecium. When the 

 reverse is the case, as in Silene and in the dog-daisy, 

 the term protandry is used, and the flowers are called 

 protandrous. 



Silene. 



In fig. 73 the partly dissected flower of a species of 

 Silene is shown. The calyx has been removed with the 

 exception of two torn strips at the base. 



In an undissected flower it is seen to be a deep tubular 

 cup made of five united sepals. The rest of the flower is 

 raised on a stalk (visible in the figure below the ovary G) 

 as though an internode were interpolated between the 

 calyx and the rest of the floral leaves. The petals are 

 five in number and are free from each other, that is to 

 say they do not cohere into a tube. Each petal has a tall 

 thin vertical stalk, the claw, and a broad horizontal lamina 

 or limb ; it is the limbs of the petals which make up the 

 conspicuous disc-like face of the flower. 



Within the petals are the ten stamens, of which seven 

 only remain in fig. 73; they will be found to be sticky 

 with nectar, or indeed dripping with the sweet fluid 

 excreted by glandular nectaries inside their bases. The 

 gynoecium (G, fig. 73) is the first instance which we 

 have met with of the coherence of more than one carpel- 

 lary leaf to form a single ovary. Here there are three 



1 The flower is said to be protogynous. 

 D. E. B. 11 



