Trees of New York State 57 



LEAF KEY TO THE SPECIES — (Continued) page 



51. Leaves dull green above, thin, 4-10 inches long Sassafras variifolium 225 



Magnolia acuminata 219 



52. Petioles ciliate, often winged-tnargined Nyssa sylvatica 310 



52. Petioles pubescent or hairy, not winged-margined 53 



53. Petioles slender, I5-2 inches long 54 



53. Petioles stout, h-lh (rarely 2) inches long 55 



54. Petioles terete, exuding a milky juice when broken . . . Madura pomifera 209 



54. Petioles grooved, not exuding a milky juice when broken 



Cornus alternifolia 317 



55. Leaves j-3 inches long, close white-woo'ly eneath Pyrus Malus 235 



55. Leaves 3-7 inches long, pale green and pubescent beneath 



Diospyros virginiana 325 

 56. Leaf-margin lobed, cleft or divided; lobes entire or variously indented . . 57 



56. Leaf-margin serrate, dentate or otherwise shallowlj' indented 75 



57. Leaves palmately veined 58 



57. Leaves pinnately veined 60 



58. Leaf-lobes 5-7, finely serrate Liquidambar Styracifiua 227 



58. Leaf-lobes 3-5, sinuately dentate with remote teeth 59 



59. Leaves 4-7 inches long, pale pubescent on the veins beneath 



Platan us occidentalis 229 

 59. Leaves 2-4 inches long, white velvety-tomentose beneath 



Populus alba, var. nivea 127 



60. Leaf-lobes bristle-pointed 61 



60. Leaf -lobes not bristle-pointed 65 



61. Leaves broadly wedge-shaped, 3-5 lobed at the summit 



Quercus marilandica 197 



61. Leaves pinnatifid or pinnately lobed 62 



62. Longest lobes of the leaf about equaling the breadth of the broadish 



middle portion of the leaf Quercus rubra 187 



Quercus rubra, var. ambigua 193 

 62. Longest lobes of the leaf 2-6 times as long as the breadth of the narrow 



middle portion of the leaf 63 



63. Leaves coriaceous, very lustrous above; petioles l|-6 inches long 



Quercus velutina 195 

 63. Leaves membranous, somewhat lustrous above; petioles 5-25 inches long. .64 



64. Leaves broadly oval to obovate; leaf-bases prevailingly cuneate 



Quercus palustris 189 

 64. Leaves oval to broadly obovate; leaf-base prevailingly obtuse or truncate 



Quercus coccinea 191 



65. Leaves truncate or broadly notched at the apex, sinuately 4-lobed 



Liriodendron tulipifera 221 



65. Leaves angled or rounded at the apex, variously lobed 66 



66. Petioles exuding a milky juice when broken 67 



66. Petioles not exuding a milky juice when broken 69 



67. Leaves velvety-tomentose beneath ; petioles 2-4 inches long 



Broussonetia papyrifera 211 



67. Leaves more or less pubescent beneath; petioles |-lj inches long 68 



68. Leaves broadly ovate to ovate-orbicular, membranous, dull above, 



conspicuously reticulate-veined Morus rubra 213 



68. Leaves ovate to ovate-oval, firm, somewhat lustrous above, not con- 



spicuouslv reticulate-veined Morus alba 215 



69. Petioles U-2^ inches long 70 



69. Petioles 3-I f inches long 71 



70. Leaves 3-lobed; margin incised-serrate Pyrus coronaria 233 



70. Leaves shallowly 8-10 lobed; margin doubly serrate 



Crataegus pedicellata 243 



71. Leaves mitten-shaped or obovate and trilobed at the top 



Sassafras variifolium 225 



71. Leaves lyrate or sinuate-pinnatifid 72 



72. Mature leaves glabrous beneath Quercus alba 175 



72. Mature leaves pubescent or tomentose beneath 73 



