KEY TO IMPORTANT WOODY PLANTS 



29 



11. Buds not resinous; true end buds lacking, twig tip dying back 

 to tiny stub at base of topmost side bud; bud scale single, 

 caplike; leaves usually relatively narrow and short-stalked, of 

 3 varying, intergrading leaf-shape types (at base, middle, and 

 tip of twig) ; twigs of 3 (or 4) kinds: 5 



(1) short, spring or early summer shoots from lower buds 

 on flowering or fruiting twigs; 



(2) long, often vigorous summer shoots from top buds of 

 fruiting twigs; 



(3) vigorous summer shoots from old wood after fruiting; 



(4) late summer or autumn sucker shoots (sometimes lack- 

 ing) from trunk or root; 



leaf margins entire or toothed, teeth sometimes gland-tipped; 

 stipules lacking, or green and often persistent, or scalelike and 



5 Unless otherwise stated, the illustration is of a mature leaf from near middle of 

 a type 2 or type 3 twig. 



Flower scale 



Seed-producing flower 



Catkin with 2-parted seed 

 pods (capsules) 



Catkins with 3-parted seed) 

 pods (capsules) 



-producing flower, 

 th flower scale 



Pollen-producing flower 

 and scale 



F-49403 1 



Quaking aspen 



Black cottonwood 



