Wild Flowers East of the Rockies 11 



have masses of pollen attached to some portion of 

 his anatomy. 



Many plants, usually annuals, whose roots die each 

 year and that are dependent entirely upon setting of 

 seed for their existence, have what are called cleis- 

 togamous flowers. These are bud-like flowers that 

 never open, but fertilize themselves in the bud. 

 These plants also have flowers that do open and that 

 try to woo insect visitors; the others are for protec- 

 tion in case of several years shortage of useful in- 

 sects. 



Just as some flowers are so careful in adapting 

 themselves to certain useful insects, they must be 

 just as careful in protecting themselves against use- 

 less ones. In general, smooth bodied insects are of 

 little value to plants, but they all like nectar. The 

 most useless visitors are crawling ones, especially 

 ants and it is against these that plants must erect 

 their barriers. 



The most frequently used preventative is a downy 

 stem. The small hairs impede upward progress and 

 often exhaust the tiny insects before they can reach 

 the flower; often the calyx is sticky and thF maraud- 

 er finds a barrier from which he must turn or risk 

 being caught on its surface. Some flowers have their 

 nectar in long slender tubes so that only moths, but- 

 terflies or long-tongued bees can reach it. Others 

 have the entrance closed with a palate, to open which 

 the weight of a bee on the platform outside is neces- 

 sary. Still others, like the Closed Gentian, are al- 

 ways closed, but the petals can be forced apart by the 

 strong bumblebee. 



Many flowers are very highly specialized, adapted 

 to be fertilized by but one species of insect. This 



