72 The Ncio York State College of Forestry 



TWIG KEY TO THE SPECIES — (Continued) page 



73. Twigs with conspicuously orange-colored pith Populus heterophylla 133 



73. Twigs with white pith 74 



74. Buds smooth, lustrous, conical, acute Populus tremuloides 129 



74. Buds downy, dull, ovate, obtuse Populus grandidentata 131 



75. Pith with cross partitions 76 



75. Pith homogeneous 79 



76. Pith diaphragmed-chambered with thin septa; twigs stout 77 



76. Pith diaphragmed-stuif ed ; twigs slender 78 



77. Buds tawny; upper margin of leaf -scar with a fringe of hairs; pith dark 



brown Juglans cinerea 141 



77. Buds grayish white; upper margin of leaf -scar without hairy fringe; pith light 



brown Juglans nigra 143 



78. Buds naked, rusty-brown-tomentose ; bimdle-scars 5-7. . .Asimina triloba 223 



78. Buds scaly, essentially glabrous; bundle-scars 3 Nyssa sylvatica 319 



79. Bundle scars 1 ; twigs green, spicy-aromatic Sassafras variif olium 225 



79. Bundle-scars more than 1 80 



80. Leaf-scars extending nearly around the stem; twigs very stout, with 



numerous cortical prickles Aralia spinosa 313 



80. Leaf -scars not extending half way around the stem 81 



81. Bimdle-scars more than 5, irregularly scattered or arranged in a curved 



line 82 



81. Bundle-scars 3-5, in a lunate hne 86 



82. Buds small; bark of twigs mottled; pith terete Rhus Vernix 285 



82. Buds large; bark of twigs not mottled; pith angular 83 



83. Buds bright yellow; bud-scales 4-6 valvate in pairs Carya cordiformis 155 



83. Buds not bright yellow; bud-scales 10 or more, imbricated 84 



84. Terminal buds chiefly less than 2/5 of an inch long: bud-scales close, 



generally glandular; twigs slender Carya glabra 153 



Carya microcarpa 151 

 84. Terminal buds chiefly more than 2/5 of an inch long; bud-scales rather 



loose, essentially glandless; twigs rather stout 85 



85. Outer bud-scales early caducous; inner bud-scales pale yellowish gray and 



silky Carya alba 149 



85. Outer bud-scales persisting through the winter Carya ovata 145 



86. Leaf-scars semi-circular to broadly lunate, i-1/5 of an inch in diameter; 



bundle-scars large, annular; older twigs often corky-winged 



Liquidambar Styraciflua 227 

 86. Leaf-scars narrowly lunate or otherwise less than | of an inch in 



diameter 87 



87. Some of the upper buds more than § of an inch in length 88 



87. Upper buds never more than ^ of an inch in length 89 



88. Buds lance-linear; bundle scars 3; pith greenish white, angular. . . . 



Amelanchier canadensis 241 



Amelanchier laevis 241 



88. Buds ovate; bundle-scars 3-5; pith brownish, terete. . . .Pyrus americana 237 



Pyrus Aucuparia 239 

 89. Internodes very unequal; branches much exceeding the parent axis. . . . 



Cornus alternifolia 317 



89. Internodes essentially equal ; branchas shorter than the parent axis 90 



90. Terminal bud narrowly ovate, its scales narrow, thickened and usually 



3-toothed Pyrus coronaria 233 



90. Terminal bud usually broadly ovate or hemispherical, its scales broadly 



ovate and thin 91 



91. Leaf-scars in ^ phyllotaxy; bud-scales thick; twigs with long slender, often 



falcate thorns Crataegus pedicellata 243 



91. Leaf-scars in 2/5 phyllotaxy; bud-scales thin; twigs imarmed or if armed, 



with branch-like spines or spurs 92 



92. Buds grayish-white, tomentose, obtuse Pyrus Mains 235 



92. Buds brownish, glabrous or slightly pubescent 93 



93. Buds conical; twigs without cherry-taste Pyrus communis 231 



93. Buds ovate, somewhat constricted below; twigs generally with cherry taste. . 



Prunus (cherries and peach) 372 



