120 



STRUCTURAL BOTANY. 



Spear-grass, Catalpa. A thyrse is a sort of compact, oblong, 01 

 pyramidal panicle, as in Lilac, Grape. 



301. 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 ca- 

 pitulum are seen in the Com- 

 posite, where the summit of 

 the peduncle, that is, the re- 

 ceptacle, is dilated, bearing the 

 sessile flowers above, and scale- 

 like bracts around, as an in- 

 volucre. 



362. The capitulum of the 

 Composite is often called, a 



COmpOUnd flower from itS re- 



-, , , 



Semblance, the 



an- 



440 



446, Vernonia fasciculata flowers in a discoid 

 head with an imbricated involucre. 447, A single 

 flower remaining on the receptacle. 448, A fruit 

 crowned with the pappus. 449, Mulgedium ahead 

 450, A single flower remaining on the receptacle. 



swenng to a calyx, the rays to ^51, A fruit with pappus. 

 the corolla. The flowers are called florets those of the outer 

 circle, florets of the ray, generally differing in form from those 

 of the central portions, the florets of the disk. 



363. Of terminal inflorescence the following varieties are 

 described: cyme, fascicle (verticillaster), and glomerule. 



.0 



454 



Diagrarc (452) of cyme; flowers numbered in the order of their development. i53, Oyme fastigiate. 

 454, Cyme half developed a scorpoid raceme. 



364. Cyme is a general term denoting any inflorescence with 

 centrifugal evolutions, but is properly applied to that level- 

 topped or fastigiate form which resembles the corymb, as in the 



