vinal] MECHANICAL AIDS IN NATURE-STUDY 71 



Austrian Pine: 2 leaves in a bundle, stiff, thick. 

 *Scotch Pine: 2 leaves in a bundle; cones point backwards. 



American Larch: deciduous; spurs; cone ^', few scales. 

 ♦European Larch: many leaves in cluster; cone 1", many scales. 



Black Spruce : cone nearly spherical, persistent. 

 ♦Norway Spruce : cone more than 3 '; leaves all around stem. 



Hemlock: leaves 2 ranked, whitened beneath, flattened. 



White Cedar : leaves awk-like ; globular cone ; swamps. 



* Arbor Vitas: 2 ranked spray; small tree; hedges. 

 Red Cedar: bluish berry; dry hills; red heart-wood. 

 Juniper: berry axillary; leaves prickly pointed, 3 in whorl. 



Willow Family 



Yellow Willow : yellow twig. 

 ♦Weeping Willow : drooping branches; ornamental. 



* White Poplar; retains whitish green bark; woolly twigs. 

 American Aspen : buds, reddish slightly sticky, appressed. 

 Large-toothed Aspen : buds downy, small. 



*Balm of Gilead : fragrant buds, resinous, large. 

 ♦Carolina Poplar: light yellow twigs; appressed buds. 

 *Lombardy Poplar: sharply up-curved branches. 

 Walnut Family 



Butternut: terminal bud longer than broad; brown pith. 



Black Walnut: nut spherical, 4 celled; pale buff pith. 



Shag-bark Hickory: white, thin shelled nut; shaggy bark. 



Mockernut: brown, thick shelled nut; smooth ridges. 



Pignut: nut nearly spherical, thick shell; slightly shaggy. 



Bitternut: thin shell; superposed buds, yellow, dotted. 

 Birch Family 



Hop Hornbeam: fruit like hop; flaky bark. 



American Hornbeam : twisted appearance to bark. 



Black Birch: dark bark, not peeling, aromatic. 



Yellow Birch: yellow bark, peeling, aromatic. 



American Canoe Birch : white bark, papery layers. 



Gray Birch : dingy, gray bark, not papery. 



Speckled Alder: cone-like catkins, lateral, erect. 



Smooth Alder: cone-like catkins, terminal, erect. 

 Beech Family 



American Beech : bluish gray bark ; long buds; dead leaves. 



Chestnut : burs; 2 ranked buds, oblique to leaf scar. 



