190 



FOUNDATIONS OF BOTANY 



compound flower. This belief gave rise to the name of 

 one family of plants, Composites, that is, plants with com- 

 pound flowers. In such heads as those of the thistle, the 

 cud weed, and the everlasting there are no ray-flowers, 

 and in others, like those of the dandelion and the chicory, 

 all the flowers are ray-flowers. 



201. Compound Flower-Clusters. — If the pedicels of a 

 raceme branch, they may produce a compound raceme, or 



-^ 



"^ 



^ 





\ 



/ 



1/ 



/ 



s 



y 



A BCD 



Fig. 136. —Diagrams of Inflorescence. 

 .^, panicle; S, raceme; C, spike; S, umbel; Z), head. 



panicle, like that of the oat (Fig. 134).^ Other forms of 

 compound racemes have received other names. 



An umbel may become compound by the branching, of 

 its flower-stalks (Fig. 135), each of which then bears a 

 little umbel, an umbellet. 



202. Inflorescence Diagrams The plan of inflorescence 



may readily be indicated by diagrams like those of Fig. 136. 



The student should construct such diagrams for some rather com- 

 plicated flower-clusters, like those of the grape, horse-chestnut or 

 buckeye, hardhack, vervain, or many grasses. 



1 Panicles may also be formed by compound cymes (see Sect. 204). 



