26 WOODY PLANTS 



163. Aromatic ; buds greenish-yellow. . .Lindera, p. 98 



163. Not aromatic; buds reddish. . . Alnus , p. 71 



164. Pith flattened or 3-angled. 165 



164. Pith round. 167 



165. Bud-scales overlapping each other. 166 



165. Bud-scales not overlapping. . . Alnus , p. 71 



166. Bud-scales 4-6. . . Corylus , p. 67 



166. Bud-scales usually 2 or 3. . . Betula, p. 68 



167. Twigs with 3 small vertical ridges below the leaf-scars. 168 



167. Not as above. 170 



168. Leaf-scars 2-ranked. . . Cercis, p. 129 



168. Leaf-scars in more than 2 ranks. 169 



169. Buds appressed;bark exfoliating. . . Physocarpus , p. 105 



169. Not as above. . . Prunus , p. 121 



170. Buds longand spine-like; stipule-scars long. . . Fagus , p. 73 



170. Not as above. 171 



171. Twigs quite thick; leaf-scars large; buds short. . . Ailanthus , p. 131 



171. Not as above. 172 



172. Buds small and appressed. 173 



172. Not as above. 176 



173. Leaf-scars on raised leaf-cushions. 174 



173. Leaf-scars low. 175 



174. Bark peeling horizontally, inner bark with a disagreeable 

 odor. . . Prunus , p. 121 



174. Bark peeling vertically; lenticels prominent. . . Rhamnus, p. 143 



175. Lateral buds triangular. . . Celtis , p. 85 



175. Lateral buds minute, not triangular. . , Cornus , p. 158 



176. Pith 5-angled, twigs often warty. . . Liquid ambar , p. 103 



176. Not as above. 177 



177. Leaf-scars 2-ranked. 178 



177. Leaf-scars in more than 2 ranks. 182 



178. Bud-scales in 2 ranks. . . Ulmus, p. 83 



178. Bud-scales not in 2 ranks. 179 



179. Bud-scales with vertical striations. . . Ostrya , p. 67 

 179. Bud-scales not striate. 180 



