126 Plants and their Ways in South Africa 



its tongue, as shown in Fig. 139. When it visits another flower 

 with long stigmas the pollen will be brushed off on the upper 

 part of the tongue, and short stigmas of a flower will brush 

 it off below. 



In Gazania and Cryptostemina the stamens are joined by 

 their anthers (syngenesious), making a collar around the 

 stigma. Watch the flowers of the disc in the centre. The 

 outer flowers of the disc open before the inner ones on succes- 

 sive days. On a bright morning the long club-shaped stigmas 

 push up through the collar, well covered with pollen. On the 



,,--<S--_ jillil'i 



Fig. 140. — Trimorphic flowers of Oxalis cerniia. The arrows indicate 

 the legitimate combinations. (From Edmonds and Rlarloth's " Ele- 

 mentary Botany for South Africa.") 



following day the elastic style has shortened, the five teeth 

 made by points of the stamens brush off the pollen and leave 

 it in little rings in each flower. These stigmas now op^en at 

 the top to receive pollen, while closed stigmas of an inner 

 whorl brush out rings of pollen from their flowers. When 

 they in turn are ready to receive they split down the 

 centre and spread apart. The fruits formed in these flowers 

 give evidence that the insects have unconsciously brushed 

 off the pollen from the stamens and delivered it to the 

 stigmas. 



Senecios, on the other hand, spread apart the stigmas in 



