xviii 



TREES 



78. Buds with lowest scale in front. p. 18. Populus. 

 Buds with lowest scales at the side. 79. 



79. Twigs very slender: toothing fine. p. 60. Amelanchier. 

 Twigs stouter: leaves never very finely serrate. 80. 



80. Leaves entire or pinnately lobed. p. 29. Quercus. 

 Leaves palmately lobed. 81. 



81. Leaves star-shaped or maple-like. p. 52. Liquidambar. 

 Leaves large with dilated lobes. p. 102. Sterculia. 



82. Buds stalked, or developing the first season. 83. 

 Buds not stalked. 84. 



83. Leaves palmately nerved and lobed. p. 52. Liquidambar. 

 Leaves pinnately veined and toothed or lobed. p. 26. Alnus. 



84. Nectar-glands on petiole or leaf-base. 

 Leaves without nectar-glands. 85. 



85. Pith chambered. 86. 

 Pith continuous. 88. 



86. Leaves thin, not revolute. 87. 

 Leaves firm, revolute: fruit fleshy. 



87. Fruit fleshy: calyx large. 

 Fruit dry, winged. 



88. Buds naked. 

 Buds scaly. 89. 



89. Leaves not lobed. 90. 

 Leaves lobed. 97. 



90. Leaves very woolly beneath, entire. 

 Leaves toothed if at all woolly. 91. 



91. Leaves firm and very glossy. 92. 

 Leaves thinner and duller. 93. 



92. Pith with firmer plates. 



Pith without firmer diaphragms. 

 Bundle-trace 1. 

 Bundle-traces 3. 



93. Leaves whitened beneath. 



p. 67. Prunus. 



p. 126. Symplocos. 



p. 125. Diospyros. 



p. 126. Halesia. 



p. 97. Rhamnus. 



p. 58. Cydonia. 



p. 111. Nyssa. 



120. Oxydendrum. 

 p. 56. Pyrus. 



p. 109. Cornus. 



Leaves not whitened unless by tomentum. 94. 



