508 



BOTANY OF THE LIVING PLANT 



Androecium, stamens 10, free, hypogynous, of varying length during flower- 

 ing. The 5 outer opposite the sepals, the 5 inner opposite the petals. 



Gynoecium, carpels 5, syncarpous, superior ; ovary unilocular, ovules 

 numerous, on free central placenta. Styles and stigmas 5, rising separately 

 from the apex of the ovary. 



Pollination. Nectar is secreted at the base of the stamens, and the flowers 

 are visited by many insects, especially butterflies and moths. The flowers 



FIG. 413. 



Dissections of flowers of Lychnis diurna. I., II., VIII., the pistillate flower in 

 which the stamens are represented only by staminodes (st). III., IV., IX., the 

 pistillate flowers in which the gynoecium is represented only by a vestigium (gyn). 



are protandrous ; in the first stage the 5 outer stamens shed their pollen at 

 the entrance of the tube ; later the 5 inner stamens do the same ; finally the 

 5 stigmas grow up and fill the entrance to the flower. An insect visiting the 

 flower in either of the first stages will remove pollen on its proboscis, which 

 it may deposit on another flower in the third stage. Intercrossing is thus 

 probable, though self-pollination is possible. 



(14) In the Red Campion (Lychnis diurna, L.), two types of plant are found : 

 some with thinner stems and smaller leaves bear only staminate flowers, others 

 with more robust habit bear pistillate flowers. These should be examined 

 and compared (Fig. 413)- In the staminate flowers the Calyx and Corolla are 



