INFLORESCENCE. 



19 



themselves umbels, as in caraway and most of the Umbelifera?, a com- 

 pound umbel is produced. Such secondary umbels are called umbelletn 

 and the primary pedicels, rays. 



352. The panicle is a compound inflorescence formed by the irregu- 

 lar branching of the pedicels of the raceme, as in oats, spear-grass, 

 Catalpa. 



353. A thyrse is a sort of compact, oblong, or pyramidal panicle, as 

 in lilac, grape. 



354. A head or capitulum is a sort of reduced umbel, having the 

 flowers all sessile upon the top of the peduncle, as in the button snake- 

 root, button-bush, clover. 



But the more common examples of 

 the capitulum are seen in the Compos- 

 ite, where the summit of the peduncle, 

 that is, the receptacle, is dilated, bear- 

 ing the sessile flowers above, and scale- 

 like bracts around, as an involucre. 



355. The capitulum of the 

 Composite is often called a com- 

 pound flower from its resem- 

 blance, the involucre answering 

 to a calyx, the rays to the corolla. 

 The flowers are called florets, 

 those of the outer circle, florets 

 of the ray, generally differing 

 in form from those of the cen- 

 tral portions, the florets of the 

 disk. 



356. Of terminal inflores- 

 cence THE FOLLOWING VARIETIES 



are described : cyme, fascicle 

 (verticilaster), glomeruli. 



218 



Vernonia fascicnlata; flowers in a discoid 

 head with an imbricated involucre. 211, A 

 single flower remaining on the receptacle. 213, 

 A fruit crowned with the pappus. 213, Malge- 

 dium ; a head. 214, A single flower remaining 

 on the receptacle. 215, A fruit with pappus. 



Diagrams ; 216 of a cyme ; flowers numbered in the order of their development 217, Cyme faa- 

 tigiate. 218, Cyme half developed— a scorpoid raceme. 



357. Cyme is a general term denoting any inflorescence with centri- 



