A Bud and Twig Key 5 



ei. Thick milky juice exudes from freshly cut bud, 

 twigs glabrous red brown, bud dark red or slight- 

 ly greenish, scales smooth and shiny. Stipular 

 line between leaf scars straight or slightly an- 

 gled. A. platanoides Linn. 



C2. Juice of bud watery. 



//. Stipular line between leaf-scars straight, twigs 

 glabrous, usually red or reddish brown, scales 

 glabrous. Plate I. '\A. saccharinum Linn. 



~\A. rubrum Linn. 



J2. Stipular line between leaf-scars usually broad 

 and sharp-angled, twigs change from green 

 through several shades of purple and red dur- 

 ing winter, often with white bloom, buds chang- 

 ing color with twigs, bud-scales often apiculate, 

 outer pair slightly pubescent, inner scales silky 

 tomentose. Plate I. A. negundo Linn. 



C2. Terminal bud long-lanceolate or flattened, one pair of 

 scales visible, Stipular line usually present, bundle- 

 scars three often united or indistinct, leaf-scars nar- 

 row lunate, especially those near base of twig. Plate 

 I. Cornus Linn. 



b2. Stipule-scars and stipular line absent. 



Cornus (see above). 



a2. Bundle-scars five to many, often nearly united, forming a 

 U-shaped line. 



bi. Terminal buds one-half inch or longer and half as 

 broad, coated with wax, many light brown scales, bun- 

 dle-scars five to seven prominent, no stipule-scars, twig 

 large, leaf-scar large shield-shaped, pith large. 



Aesculus Linn. 



f It is difficult to distinguish between these two species without leaves 

 or fruit. A. saccharinum often has apiculate bud-scales and rather long, 

 narrow buds while A. rubnitn rarely has apiculate scales and usually quite 

 globular buds. 



