518 



BOTANY 



violet, and red seem to be more specialized colors, and are found in 

 many of the most highly developed flowers. Red flowers are espe- 

 cially attractive to humming-birds, which are the principal agents in 

 the pollination of many scarlet flowers. 



While many insects visit the flowers for the pollen, most ento- 

 mophilous flowers produce nectar, which is the principal object of 



the visits of insects 

 and birds. 



The more primi- 

 tive types of flowers 

 usually are actino- 

 morphic, and are 

 widely open so that 

 they are accessible 

 to a great variety 

 of insect visitors. 

 Such flowers as 

 Ranunculus, or 

 Rosa, are of this 

 character, and the 

 wide-open heads of 

 many Compositse, 

 although decidedly 

 more specialized 

 than the former 

 flowers, neverthe- 

 less are visited by 

 many kinds of 

 insects. 



FIG. 486. Canna sp. The petals, c, and sepals, s, are These entomo- 

 inconspicuous, the showy part of the flower being the philous flowers are 

 petaloid stamens, or staminodia, a. (After BAILEY.) almogt alwayg cQn _ 



spicuously colored, and the petals are in most cases the showy part of 

 the flower. Sometimes, however, as in Anemone (Fig. 487), the petals 

 are absent, and the sepals are large and petaloid. In Fuchsia both 

 sepals and petals are showy, and the same is true of most Monocoty- 

 ledons. Sometimes, as in the flowering Dogwood (Cornus florida), 

 species of Euphorbia, many Araceae, Bougainvillea, etc., the flowers 

 are inconspicuous, but are surrounded by showy bracts, which make 

 the inflorescence conspicuous. Less frequently it is the stamens 

 which make the flower noticeable, as in Eucalyptus, where the 

 petals are undeveloped, but the numerous white or red stamens are 

 very showy. Among Monocotyledons the genus Canna is notable 

 for the brilliant petaloid stamens which constitute the attractive 

 part of the flower (Fig. 486). 



