4 A Bud and Twig Key 



The terms used throughout the Key are common to system- 

 atic botany or are self-explanatory, with the exception of a few 

 that might be readily misconstrued, among which are the fol- 

 lowing : 



Tip-scar, a term used to designate the scar left when the tip of the 

 twig is deciduous and has dropped off. A few genera have 

 formed the habit of casting the end of the twig in early sum- 

 mer and allowing the growth of the next season to be contin- 

 ued through the uppermost lateral bud.* 



Twig, a term used to designate the part of the branch that made 

 its elongation growth during the last growing season. 



Terminal bud, the bud at the end of the twig on those twigs which 

 do not have a deciduous tip. 



DECIDUOUS BROAD-LEAF TREKS. 



7. Leaf-scars whorled, three (rarely two) at each node, oval 

 with many bundle-scars in a line forming an ellipse, no stip- 

 ule-scars, no terminal bud, tip-scar prominent, twig large, 

 buds small globular partially sunk in bark. Plate I. 



* Cat alp a Scop. 

 II. Leaf-scars opposite, two at each node. 



ai. Bundle-scars three forming a lunate line. 



bi. Stipule-scars represented by a line connecting leaf-scars. 

 CT. Terminal bud one-eighth to one-fourth inch long, two 

 or more pair of scales visible, stipular line always 

 present, leaf-scars narrow lunate. 

 Acer Linn. (Except A. macrophyllum. See page 6.) 

 di. Terminal bud acuminate dark brown, conical with 

 five or six pair of scales visible, twigs brown gla- 

 brous, stipular line straight. Plate I. 



A. sac ch arum Marsh. 



. d2. Terminal bud red or greenish with two pair of 

 scales visible, buds obtuse or globular. 



* "Twigs of Woody Plants/' A. S. Hitchcock, The Plant World, Vol. 

 9, No. i, January, 1909. 



* It is not possible to distinguish the species of Catalpa by the twig 

 and bud. 



