2. Stipule-scars not encircling the stem, often small. 



Tilia (Lindens) . Pith cylindrical, continuous. 



Castanea (Chestnuts). Pith sharp-angled, continuous. 



Celtis OCCidentalis (Hackberrt) . Pith cylindrical, chambered. 



3. Stipule-sca/)-s obsolete or none. 



a. Pith chambered, often angled. 

 Juglans (Walnuts) . Leaf-scars large, three-lobed. 



b. Pith continuous, cylindrical. 



Cladrastis tiuctoria (Yellow-wood). Leaf-scars nearly encir- 

 cling buds. Bundle-scars five. Wood yellow. Pith mostly pale or 

 pinkish, narrow. Buds more or less conical, often superposed. 



Gymnocladus Canadensis (Kentucky Coffee Tree). Leaf- 

 scars broadly U-shaped or crescentic. Bundle-scars in three to five 

 groups. Wood yellowish. Pith brownish red. Buds depressed, sur- 

 rounded by an incurved, hairy ring of bark, superposed. 



Ailanthus glandulosus (Chinese Sumach). Leaf-scars broadly 

 U-shaped or semi-oval. Bundle-scars seven to nine. Wood pale. Pith 

 brownish, very broad. Buds depressed-globose, not superposed. 



e. Pith continuous, angled. 



Carya (Hickories, certain species). Leaf-scars more or less three- 

 lobed. Pith brownish. Buds ovoid or elongated, often superposed. 



C. Buds covered by several scales or rudimentary leaves, seldom very 



hawy. 



1. Bundle-scars usually five or more, sometimes in three groups. 



a. Buds ovoid. 



Carya (Hickories, certain species) . Buds often superposed, only 

 one or two at the tip of a. twig. Bud-scales several, spirally arranged, 

 large. 



Quercus (Oaks). Buds never superposed, sometimes collateral, 

 several or many clustered at the tip of a twig. Bud-scales numerous, 

 opposite in several ranks, small, 



b. Buds elongated. 



FagUS (Beeches). Buds solitary. Bnd-scales of medium size, in 

 two or more ranks. Branchlets with slender spurs, usually in two ranks. 



C. Buds depressed. 



Ginkgo biloba (Maidenhair Tree). Buds solitary. Bud-scalles 

 spirally arranged, small. Branchlets with numerous short, stout spurs in 

 several ranks. 



