BUDS AND BRANCHES 



143 



FIG. 169. Corymb 

 of plum blossoms. 



Fio. 170. Umbel of milk- 

 weed. 



duncle, from which they spread in every direction like the 

 rays of an umbrella, as the name implies. This is the preva- 

 lent type of flower cluster in the parsley family, which takes 

 its botanical name, Umbelliferce,iTom 

 its characteristic 

 form of inflores- 

 cence. The pedi- 

 cels of an umbel 

 are called rays, and 

 the circle of bracts 

 at the base of the 

 cluster is an invo- 

 lucre. 



162. Determi- 

 nate, or cymose, 



inflorescence. In the cyme, the typical cluster of the de- 

 terminate kind, the older blossoms in the center, being ter- 

 minal, stop the axis of growth in that direction and force the 

 stem, in continuing its growth, to send out side branches 

 from the axils of the topmost leaves, in 

 a manner precisely 

 similar to the two- 

 forked branching of 

 stems like the horse- 

 chestnut and jimson 

 weed. When the older 

 peduncles are length- 

 ened as described in 

 161, a flat-topped cyme 

 is produced, which is 

 distinguished from the 

 of grass, a compound corymb by its order of 



cluster, the racemose flowering? the oMest 



blossoms being at the 

 center, while in the corymb they appear in the reverse 

 order. A peculiar form of cyme is found in the scorpioid 



FIG. 171. Panicle 



FIG. 172. Flat-topped 

 cyme of sneezeweed. 



