141 Leaves in more than 2 ranks 142 



141 Leaves 2-ranked 145 



142 No stipule-scars visible 143 



142 Stipule-scars present 144 



143 Twigs warty; bud-scales often pitted; leaves somewhat heart- 



shaped, with double, long-pointed teeth 



MADDEN CHERRY (MADDENIA) 



143 Twigs not warty; both scales and leaves not as just described 



137 and 138 



144 Buds showing dark scales with white hairs around the margin 



APRICOT (PRUNUS) 



144 Scales of buds without contrasting white hairs, sometimes 



pitted PLUM (PRUNUS) 



145 Bud-scales numerous, arranged in 4 ranks 146 



145 Bud-scales about 6 in number, in 2 ranks or spiral 147 



146 Leaves single-toothed; bark of trunk scaly (ZELKOVA) 



146 Leaves irregularly or doubly toothed ; bark of trunk gray, ridg- 



ed like muscles on an arm 



HORNBEAM, BLUE BEECH (CARPINUS) 



147 Bud-scales striped vertically; catkins often present; leaves not 



very lop-sided at base of blade 



IRONWOOD, HOP-HORNBEAM (OSTRYA) 

 147 Bud-scales not striped, but smooth or hairy; catkins not pres- 

 ent; leaves lop-sided at base of blade ELM (ULMUS) 



COMPOUND LEAVES 



148 Most or all leaves made up of only 3 leaflets 149 



148 Most or all leaves made up of more than 3 leaflets 153 



149 Leaves opposite, but not always quite on the same level 150 



149 Most or all leaves spirally arranged _ 151 



150 Winter-buds showing 2 or 4 scales; leaflets finely toothed; up- 

 per margin of leaf-scars almost straight 



BLADDERNUT (STAPHYLEA) 



150 Winter-buds many-scaled and leaflets variously toothed, or 2- 

 or 4-scaled and leaflets coarsely or doubly toothed ; upper 



margin of leaf-scars curving down MAPLE (ACER) 



23 



