CH. V] ACCESSORY BUDS 37 



long shoots are developed only in the axils of a very few 

 of the numerous leaves, e.g. Silver Fir, Spruce, Douglas 

 Fir, &c. 



On the other hand, the rule of one bud to each leaf- 

 axil is broken by many plants which develop extra or 

 accessory buds, either side by side with the truly axillary 

 bud, or superposed on the latter in a vertical series, or 

 even according to both modes of aggregation in the 

 same axil. 



For instance, the accessory buds are superposed in 

 certain species of 



Lonicera Carya Sambucus 



Fraxinus Jasminum Sophora 



Cercis Juglans Rubus 



Celastrus Albizzia Spircea 



Cornus Laurus Clerodendron. 



They are side by side, or collateral, in certain species of 



Salix Punica Polygonum 



Cercis Acer Prunus 



Zelkova Symphoricarpos. 



In certain species of the following the accessory buds 

 occur both superposed and collateral : 



Aristolochia Lycium. 



Arid in one and the same genus we may have the buds 

 sometimes superposed, e.g. Cercis canadensis, Sambucus 

 nigra ; and at others side by side, e.g. Cercis siliquastrum, 

 Sambucus racemosa. 



These cases must not be confounded with those where 

 buds are apt to be aggregated at the ends of the shoot, 

 e.g. Oaks and Prunus; or where paired opposite buds 

 occupy the apex, because the true terminal bud is 

 aborted, e.g. Syringa. 



