FIELD BOOK OF PONDS AND STREAMS 



the large barrel-shaped pistil and yellow-green stamens are 

 packed closely against its sides (Fig. 75). During the first 

 day of bloom the flower cup opens only slightly but enough 



Fig. 75. — Yellow pond-lily, Nymphcea advena: i, 

 flower; 2, flower cut to show the barrel-shaped pistil 

 and the stamens surrounding its base; 3, leaf. 



to admit insects which come laden with pollen from other 

 flowers, brushing it on to the stigma already ripe to receive 



92 



