90 Principles of Plant Culture. 



their flowers or the product of their flowers, i. e., fruit 

 or seed. But the flower is not an essential part of the 

 plant, and instead of contributing to its welfare, as do 

 the leaves and roots, it actually consumes a part of the 

 plant's reserve food (140). As might be expected, there- 

 fore, perennial plants do not always produce an annual 

 crop of flowers, even when well developed in other direc- 

 tions, hence the grower is often disappointed. Since 

 flowers can only come from flower-buds, a knowledge of 

 the laws that govern the formation of these would often 

 be valuable to the cultivator. Unfortunately, this sub- 

 ject has received less attention than is due to it. Two 

 principles may be cited, however, which if they do not 

 explain all phenomena connected with the formation of 

 flower- buds, are of sufficient general application to have 

 ^reat economic value, viz: 



A — Plants form flower-buds only when they contain re- 

 serve food (85). 



B — A water supply insufficient for rapid groioth may suf- 

 fice for abundant food formution (59). 



In support of the first of these propositions, we men- 

 tion: (a) Rapidly-growing plants rarely form many 

 flower- buds because the food is used up in growth as fast 

 as formed, (b) Checking such rapid growth, by remov- 

 ing the growing points of the stem or root (67), or by 

 "withholding water, results in an accumulation of food 

 and is often followed by an abundant formation of flower- 

 buds, (c) Obstructing the rootward current of prepared 

 food (80), as by "ringing" (416 g) causes an accumula- 

 tion of food above the obstruction and is often followed 

 by the formation of flower-buds in that part. 



