158 



INDEFINITE INFLORESCENCE. 



it in a radiating or umbrella-like manner, and end in small umbels, o', 

 which are called partial umbels or umbellules, to distinguish them from 

 the general umbel arising from the primary axis. This inflorescence is 

 seen in Hemlock, and other allied plants, which are hence called 

 Umbelliferous. 



336. If there are numerous flowers on a 

 flattened convex or slightly concave recep- 

 tacle, having either very short pedicels or 

 none, a capitulum (a head) or anthodium 

 oLv6o$, a flower, &<>;, a way or method), or 

 calathium (xx^oidtov, a small cup), is formed 

 as in Dandelion, Daisy, and other composite 

 plants, (figs. 242 and 243); or a glomerulus* 

 (a ball), as in Scabiosa (fig. 232), and in 

 Dipsacus (fig. 244). Such a receptacle or 

 flattened peduncle may sometimes be folded 

 so as to enclose partially or completely a 

 number of flowers (generally unisexual), 



* By some this term Is applied to the centrifugal inflorescence of certain Urticacece, Chenopo- 

 diacea?, and Juncaceae. 



Fig. 241. Compound umbel of Carrot (Daucus Carota). of, Primary axis shortened and 

 depressed, so as to present a convex surface, a" a", Secondary axes or radii of the general um- 

 bel, each ending in a partial umbel or umbellule, o" o" o" o". a'" a"', Tertiary axes or radii of 

 the partial umbels or umbellules. i', Pinnatipartite bracts, forming the general involucre, t" if, 

 Simple bracts, forming the partial involucre or involucel. 



Fig. 242. Capitulum, Anthodium, or Head of flowers of Scorzonera hispanica. 6, Imbricated 

 bracts, forming an involucre. /, Florets or small flowers on the receptacle, having a centripetal 

 evolution. 



Fig. 243. The same Capitulum cut vertically, r, The Receptacle, Phoranthium, or the- flat- 

 tened and depressed apex of the peduncle, bearing the florets, /, which are surrounded by bracts, (>. 



