90 



Elementary Work in Botany. 



Classify your flowers and describe their forms. Try to 

 decide what must be some of the characteristics of their 

 insect aids. Get as many kinds of flower clusters as possible 

 for the next exercise. 



EXERCISE 48. 



The Forms of Flower Clusters. You have already 

 learned that flowers are either at the ends of stems or 



between leaves and stems; 

 that is, they are either termi- 

 nal or axillary. Flower clus- 

 ters are also terminal or 

 axillary, and the flowers in 

 the clusters are terminal or 

 axillary in relation to the ped- 

 uncle or axis of the cluster. 

 Often a terminal cluster is 

 made up of flowers which 

 grow in the axils of bracts; 

 that is, the inflorescence is 

 axillary. Sometimes an axil- 

 lary cluster is composed of 

 flowers which are terminal. 



Fig. 7 1 represents forms of 

 simple axillary inflorescence. Shortening an ordinary stem 

 with axillary flowers and reducing the leaves to bracts 

 would give it the appearance shown at a in the figure. A 

 raceme, then, is a stem with very short internodes bearing 

 flowers in the axils of bracts. Note that the oldest flower 



Fig. 70. Cypripedium, or moccasin flower. 



r. Sepals; the lower pair united, pp. The 

 lateral pair of petals. The lower one forms a 

 sac which is the conspicuous part of the 

 flower, c. The column formed by the united 

 s amens and stigma, o. The inferior ovary. 



