Part 75

Tomentose. Densely pubescent with matted wool.

Toothed. With teeth or short projections.

Torus. The part of the axis of a flower which bears the floral organs.

Transverse. Said of a wood section made at right angles with the axis of the stem; across the grain.

Tree. Usually defined as a plant with a woody stem, unbranched at or near the base, reaching a height of at least 15 feet.

Trunk. The main stem of a tree.

Turbinate. Top-shaped.

Umbel. A simple inflorescence of flowers on pedicels which radiate from the same point. Page XIV.

Umbellate. Arranged in umbels.

Undulate. With a wavy margin or surface. Page XIII.

Unisexual. Of one sex, either staminate or pistillate; not perfect.

Veins. Threads of fibro-vascular tissue in a leaf, petal, or other flat organ.

Villose or Villous. Covered with long, soft hairs.

Viscid. Glutinous; sticky.

Whorl. An arrangement of leaves or branches in a circle round an axis.

Wood. The hard part of a stem lying between the pith and the bark.

Woolly. Covered with long and matted or tangled hairs.

INDEX TO THE ARTIFICIAL KEYS

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.

INDEX TO THE TREES

Abies balsamea, 27.

Acacia, Three-thorned, 165.

Acer dasycarpum, 185. negundo, 193. nigrum, 183. pennsylvanicum, 177. platanoides, 189. pseudo-platanus, 191. rubrum, 187. saccharinum, 181, 185. saccharum, 181, 189. saccharum nigrum, 183. spicatum, 179.

Aesculus glabra, 199. hippocastanum, 197. hippocastanum, v. flòre plèno, 197.

Ailanthus, 171. glandulosa, 171.