304 



TYPICAL FLOWERING PLANTS 



into honey, or they find pollen, which they eat and feed 

 to their young. Insects are attracted to flowers by their 

 strong odor or bright colors, or by both. 



One of the most interesting studies in biology is the 

 relation which exists between certain flowers and the 

 insects which pollinate them. In the case of salvia or 



flowering sage, for example, the ir- 

 regular corolla offers the bee a con- 

 venient place to alight. To suck up 

 the nectar the bee must push its head 

 into the cup of the flower where it is 

 forced to brush against the stigma 

 which becomes covered with the pollen 

 from the last salvia flower which the 

 bee visited. When the bee withdraws 

 its head it becomes dusted with pollen 

 from the anthers which bend down 

 and touch the back of the insect. 

 The stamens and pistil of salvia do 

 not mature at the same time (Figure 

 317), so that the bee can carry pollen 

 only from flowers in which the stamens 

 are ripe ; and the pistil will receive 

 pollen only in the flowers that have a 

 ripe pistil. 



Certain orchids have deep tubes 

 from which the nectar can be drawn 

 only by insects like large moths which have long sucking 

 organs. Many orchids have their pollen in masses. 

 These masses stick to the head of the insect visitor, 

 and hang down while it is passing to another flower. 

 In this position the mass is almost certain to be rubbed 

 off on the stigma of the second flower. Red clover 

 is dependent on bumble bees for pollination, for they 



Figure 316. — Flower 

 of Columbine. 



Showing spurred 

 petals. Only a long- 

 tongued insect can 

 reach the nectar. Note 

 the bunch of stamens 

 upon which the insect 

 alights. 



