22 Bulletin 194 



jj. Trunk not fluted ; catkins usually present in 

 winter ; lenticels elongated horizontally ; large 



trees Betula, p. 97. 



a. Bark flaky or rough-ridged, not warty nor peel- 

 ing off in papery layers. 



y. Bundle-scars depressed, conspicuous ; bark 

 thick, more or less deeply furrowed, 



Ulmus, p. 129. 



jj. Bundle-scars not depressed, inconspicuous ; 



bark thin, broken into narrow, flattish strips, 



loose at the ends Ostrya, p. 93. 



gg. Stipule-scars absent Prunus, p. 149. 



ee. Bundle-scars 4-many. 



/. Bundle-scars in a single U-shaped line. 



g. Terminal bud present ; fruit berry-like ; a shrub or 



small tree Pyrus, p. 143. 



gg. Terminal bud absent ; fruit not berry-like ; large trees. 

 //. Stipule-scars encircling the twig ; leaf-scars nearly 

 surrounding the bud ; bark peeling oft' in thin plates, 

 exposing the lighter colored inner bark, 



Platanus, p. 141. 

 Jih. Stipule-scars not encircling the twig; leaf-scars not 

 nearly surrounding the bud ; bark thick, rough- 

 ridged, not exposing the inner bark, 



Ulmus, p. 129. 

 ff. Bundle-scars variously grouped or scattered, but not in 

 a single line. 



g. Terminal bud present. 

 h. Stipule-scars present. 



i. Stipule-scars encircling the twig ; visible bud- 

 scales 2, united Liriodendron, p. 139. 



ii. Stipule-scars not encircling the twig ; visible bud- 

 scales more than 2, not united. 

 j. Buds 4 times as long as broad, not clustered at 

 the tips of vigorous shoots ; fruit a prickly 



bur Fagus, p. 107. 



jj. Buds not 4 times as long as broad, usually 

 clustered at the tips of vigorous shoots; fruit 



an acorn Quercus, p. 113. 



Iih. Stipule-scars absent Carya, p. 83. 



