Howard and howard. 15 



coluiun. Simultaneously tiie styles elongate and carry the stig- 

 mas into the air beyond the opening of the column and at this 

 stage pollen grains are rarely seen on the stigmas. Sometimes, 

 however, the styles bend outwards and carry the stigmas on to the 

 pollen, thus bringing about self-pollination. Frequently no pollen 

 is seen on the stigmas when the flowers begin to close about midday. 

 If closed flowers, however, are opened carefully it is foimd they 

 are always well pollinated. Self-pollination is effected almost 

 entirely by the closing of the corolla. The limb of the petal is 

 thin, the claw very thick. The corolla closes by the falling 

 towards the centre and twisting of the thin limbs. This brings 

 the corolla in contact with the burst anthers and the completion 

 of the closing of the flowers covers the stigmas with pollen. 



It will be seen that the flowers are adapted both for cross and 

 self-pollination. From the time the styles begin to carry the 

 stigmas beyond the opening of the column to the closing of the 

 flower crossing is possible. Self-pollination, however, may also 

 occur during this period. A sufficient supply of seed is ensured 

 by the very effective method of selfing when the flower closes. 



The flowers of this species do not set seed under bag in the 

 ordinary way unless artificially self-pollinated. This is due to the 

 fact that the flowers do. not close normally in the bag. The thin 

 limbs of the corolla do not fall together and twist in the iisual 

 manner, possibly on account of the even humidity of the air both 

 outside and within the closing corolla. 



The production of a sufficient supply of selfed seed from a 

 single plant in this crop is an exceedingly tedious operation. It 

 has already been stated that the flowers do not set seed under bag 

 in the ordinary way on account of the failure of the closing mechan- 

 ism of the corolla under such conditions. The flower buds have 

 to be bagged singly in the evening and selfed the followuig morning 

 about 9 to 10 A.M. when the anthers are ready to burst the moment 

 the bag is removed. Except when grown singly or at the edges 

 of a plot this crop does not branch much. As the flowers usually 

 open singly and are borne in acropetal succession on the main 



