S02 POLLINATIO.\ OF CYAN ELLA CAPENSIS. 



1. Cross-pollination: Here the large anterior anther evidently 

 plans an important role, but this I (have not been able to verify. • 



2. Self-pollination (first stage) : The relation of the posi- 

 tions of the stigmas and the two lateral stamens as described 

 above renders self-pollination very possible as any pollen falling 

 from the terminal slits of the anthers would probably strike the 

 stigmas and adhere there. In some of the flowers kept in the 

 herbarium this actually happened, and would in all probability 

 be much more frequent in the field where the flowers are often 

 violently shaken by the wind. 



3. Self-pollination (second stage) : As stated above, some 

 of the flowers which closed before any pollen was observed on 

 the stigmas yet managed to set fruit, and the pollination in this 

 case is brought about by the posterior anthers. As the perianth- 

 segments begin to close, the anterior anther, and with it the 

 style, is lifted up by the moving segments, and eventually all the 

 stamens will close together. While this is happening the three 

 posterior anthers exude drops of fluid from their apices which, 

 owing to the position of the style, cannot fail reaching the stigmas 

 and so effect pollination. 



I examined this fluid from the stamens and found that it 

 contained numerous pollen-grains. The pollen of Cyanella 

 capensis thus retains its power of germination for at least a week, 

 i.e., for tihe first dehiscence of the anthers to the closing of the 

 flower. As a further proof of this the pollen-grains from the 

 three sets of anthers, and taken from an almost closed flower, 

 were got to germinate in a cultural solution of 1.5 per cent, 

 gelatine and 15 per cent, sugar. 



The perianth a day or two after the flower has closed be- 

 comes dry and rigid and falls off entire with the stamens by 

 means of a circular split at the base. The young ifruit assumes 

 a vertical position and matures. 



Summary. 



In Cyanella capensis the bud is at first vertical then becomes 

 horizontal, and finally pendulous; in the latter stage it expands. 

 The flower is protandrous, and the six stamens are arranged in 

 ■three groups of 3. 2. and i. The tip of the style curves upwards 

 and the stigmas lie near the apices of the lateral stamens in such 

 a position as to favour self-pollination. As the flower closes the 

 posterior stamens exude a fluid laden with pollen grains, which 

 ensures pollination if other methods fail. The flower is also 

 pvidentlv adapted to cross-pollination by insects, but this has not 

 been verified. 



Division of Botany, 



Department of Agriculture, 

 Pretoria. 



