A Bud and Twig Key 



21 



. Pith round, no terminal bud, leaf-scars 

 two-ranked on the twig, many bud-scales. 



ii. Pith-rays in a one-sixteenth inch diam- 

 eter branchlet distinctly visible with 

 hand lens, twigs about one-thirty-second 

 inch in diameter, leaf-scars very small, 

 stipule-scars minute, bud about one- 

 eighth inch long, twig dark red lustrous 

 becoming when about one-half inch di- 

 ameter dull gray, tip-scar very small, 

 often dead tip of twig extends past the 

 end bud, bundle-scars three. Plate VI. 

 * Carpimts caroliniana Walt. 



P qrandidentata 



CarpiniM caroliniana 



PLATE VI. 



C Cross-section of twig. 

 L Leaf-scar magnified. 



12. Pith-rays in small branchlet scarcely or 

 not at all visible with hand lens, twigs 

 one-sixteenth inch or larger. 

 ji. Bundle-scars three- to six depressed 

 in corky layer of leaf-scar, tip-scar 

 distinct, stipule-scars small, twigs zig- 

 zag usually larger than one-sixteenth 

 inch, light brown, bud scales with 

 rounded apex. * Ulmus Linn. 



* Compare Ostrya virginiana. 

 and Primus serotina. 



Ulritus americana, Carpinus caroliniana 



