INDEX TO THE ARTIFICIAL KEYS
Reading edition
Summer Keys:
Key to the genera, xxi. Key to the species of Acer, 172. Key to the species of Aesculus, 194. Key to the species of Betula, 84. Key to the species of Carya, 66. Key to the species of Catalpa, 222. Key to the species of Cornus, 202. Key to the species of Fraxinus, 210. Key to the species of Juglans, 60. Key to the species of Picea, 18. Key to the species of Pinus, 4. Key to the species of Populus, 44. Key to the species of Prunus, 152. Key to the species of Pyrus, 142. Key to the species of Quercus, 96. Key to the species of Salix, 34. Key to the species of Ulmus, 122.
Winter Keys:
Key to the genera, xxvii. Key to the species of Acer, 174. Key to the species of Aesculus, 195. Key to the species of Betula, 85. Key to the species of Carya, 67. Key to the species of Catalpa, 223. Key to the species of Cornus, 203. Key to the species of Fraxinus, 211. Key to the species of Juglans, 61. Key to the species of Picea, 19. Key to the species of Pinus, 5. Key to the species of Populus, 45. Key to the species of Prunus, 153. Key to the species of Pyrus, 143. Key to the species of Quercus, 98. Key to the species of Salix, 34. Key to the species of Ulmus, 123.