BUDS AND BRANCHES 



143 



Fig. 169. — Corymb 

 of plum blossoms. 



Umbel of milk- 



duncle, from which they spread in every direction Uke the 

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

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

 its botanical name, Umbelliferce, from 

 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 cymes e, 

 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. "WTien the older 

 peduncles are length- 

 ened as described in 

 161 , a flat-topped cyme 

 is produced, which is 

 — Panicin <^i^^i"Siii>^hed from the 

 of grass, a rompouiid coryiiil) by its ordcr of 



cluster of the racemose n 



flowering 



type. 



center, 

 order. 



while 



the oldest 

 blossoms being at the 

 the corymb they appear 



Fig. 172.— Flat-topped 

 cynu- of sncozcwecd. 



the 



A peculiar form of cyme is found in the scorpioid 



