174 



MEMOIRS OF THE XEW YORK BOTANICAL GAKDEX 



EXPLANATION OF PLATE 2i 



During- normal flower-behavior each avocado flower opens for two 

 different periods. The appearance during the first anthesis is shown here 

 (enlarged about 2 times). The stamens do not shed pollen but stand 

 away from the pistil, leaving it exposed and in a position to be pollinated. 

 As sho^vn in the insert, the stigmatie end of the pistil is white and evi- 

 dently' in a condition for pollination. The shape and size of the stigma 

 ditfer for different varieties and its structure is rather intricate and 

 delicate. During this first opening the flower functions only as a female. 



The flowers here shown are of the Taylor variety and the picture 

 was taken at 10:00 A. J\L In this variety a set of flowers is open in the 

 first or female opening for several hours each forenoon. These flowers 

 close during midday and open for the second or male opening during the 

 afternoon of the following day. 



The male and female organs in each flower develop at different times 

 (a condition known as dichogamy). This limits or prevents self-pollin- 

 ation of individual flowers. 



At a is shown a pistil with fresh stiginatic surface as it appears in the 

 first anthesis. 



J 



