BUDS AND BRANCHES 



141 



III. THE BRANCHING OF FLOWER STEMS 



Material. — Typical flower clusters illustrating the definite and 

 indefinite modes of inflorescence. Some of those mentioned in the text 

 are: — 



Indefinite: hyacmth, shepherd's purse, wallflower, carrot, lilac, blue 

 grass, smartwecd (Polygonum), wheat, oak, willow, clover. 



Definite: chickweed, spurge {Euphorbia), comfrey, dead nettle, etc. 

 Any examples illustrating the principal kinds of cluster will answer. 



159. Inflorescence is a term 

 used to denote the position and 

 arrangement of flowers on the 

 stem. It is merely a mode of 

 branching, and follows the same 

 laws that govern the branching 

 of ordinary stems. 



The stalk that bears a flower 

 is called the peduncle. In a 

 cluster the main axis is the com- 

 mon peduncle, and the separate 

 flower stalks are pedicels. A sim- 

 ple leafless flower stalk that rises 

 directly from the ground, like 

 those of the dandelion and daffo- 

 dil, is called a scape (Fig. 165). 



160. Two kinds of inflores- 

 cence. — The growth of flower stems, like that of leaf stems, 



is of two principal kinds, definite and 

 indefinite, or, as it is frequently ex- 

 pressed, determinate and indetermi- 

 nate. The simplest kind of each is 

 the solitary, a single flower either 

 terminating the main axis, as the 

 tulip, daffodil, trillium, magnolia, 

 etc., or springing singly from the axils, as the running peri- 

 winkle, moneywort, and cotton. 



Fig. 165. - 

 flower of a lily. 



Solitary terminal 



Fig. 160. — Indeterminate 

 inflorescence of moneywort. 

 (After Gray.) 



