1 86 



BUDS AND BRANCHES 



261. Forms of Vernation. — TKe varieties of vernation 

 or prefoliation should be studied and diagrammed as they 

 are met with. In addition to the varieties already men- 

 tioned, there are the 



Straight: not bent or folded in any way, as 

 Japan honeysuckle, periwinkle, St. John's- 

 wort, dogwood, etc. 



Involute (Fig. 344): violet, arrow grass 



{Sagittarid), lotus, water lily, balm of Gilead. 



Revohcte (Fig. 343) : dock, willow oak, 



scarlet morning-glory {Ipomea 



coccined), rosemary, azalea, 



persimmon. 



Circinnate (Fig. 346) : ferns, 

 sundew. 



346. — Circinnate 

 bud of fern. 



262. Dormant Buds. — A bud 



may often lie dormant for 

 months or even years, and 

 then, through the injury or destruction of 

 its stronger rivals, or some other favoring 

 cause, develop into a branch. Such buds are 

 said to be latent or dormant. The sprouts 

 that often put up from the stumps of felled 

 trees originate from this source. 



347. — Twig of 

 red maple, show- 

 ing supernumer- 

 aiy bud, b\ rs^ 

 ring of scars left 

 by last year's 

 bud scales {after 

 Gray). 



263. Supernumerary Buds. — Where more 

 than one bud develops at a node, as is so 

 often the case in the oak, maple, honey locust, 

 etc., all except the normal one in the axil are supernumerary 

 or accessory. These must not be confounded with adventi- 

 tious buds, or those that occur elsewhere than at a node. 



PRACTICAL QUESTIONS 



1. Why do annuals and herbaceous plants generally have unpro- 

 tected buds? (252.) 



2. Why is the gummy coating found on the buds of the horse-chest- 

 nut and balm of Gilead wanting in their southern representatives, the 

 buckeye and silver poplar? (252.) 



