202 TREES IN WINTER 



91. Twigs hairy 92 



91. Twig-s smooth or nearly so, cones cylindrical 94 



92. Cones cylindrical, more than 3 inches long; cultivated species .... 

 ]Vorv*'ay Spruce (Picea AhiesJ ii.232 



92. Cones ovate to oblong, less than 3 inches long 93 



93. Leaves dark yellowish green, i^-% inch long. Cones ovate-oblong 

 114-2 inches long; a tree growing on uplands, rarely in wet places, 

 reaching 40 ft. or more in height. . . Red Spruce (Picea rubra) p.226 



93. Leaves bluish green, Vi-V2 inch long, cones ovate, %-li/^ inches 

 long, persistent on tree for more than a year; a tree growing 

 chiefly in swamps or lowlands, generally under 30 ft. in height, 



sometimes fruiting when less than 5 ft. high 



Black Spruce (Picea mariana) p.22S 



94. Leaves green, cones 4-7 inches long, cultivated species 



NorvFay Spruce (Picea Abies) p.232 



94. Leaves bluish green or silvery 95 



95. Cones 2i/^-4 inches long, cone scales distinctly longer than broad 

 with narrowed, ragged, blunt apex; cultivated western, species. 

 Blue Spruce (Picea Menziesii) p.230 



95. Cones l%-2 inches long, cone scales rounded, not ragged; leaves 

 generally with unpleasant odor, native in northern New England 

 but cultivated further south. White Spruce (Picea canadensis) p.224 



THE POPLARS 



Populus. 



Rapidly growing trees generally with erect more or less continuous 

 trunk forming distinct whorls of branches at top of each year's growth 

 by which the age of the tree may be estimated; branchlets brittle 

 easily separating at point of attachment; young bark smooth, generally 

 light colored; pith, 5-pointed star-shaped, upon drying generally turning 

 brown or black; leaf-scars large, 3-lobed, inverted triangular, covered 

 with a light colored corky layer; stipule-scars generally distinct, narrow; 

 bundle-scars 3, simple or compound in 3 groups; buds with the first 

 scale anterior (facing outward), the first pair of scales small and 

 opposite; scale-scars marking annual growth persisting for several 

 years; seeds downy, produced from catkins in spring, the tree often 

 spreading widely by formation of root suckers. The Poplars are 

 dioecious. They resemble the Willows but are easily distinguished 

 by the num-erous scales to the bud. In addition to the native species 

 here described a rare form, the Downy Poplar [Populus heterophylla L.], 

 occurs locally in swamps in southern New England. 



96. Twigs covered at least at apex with white cottony felt which may 



be readily rubbed off exposing the greenish bark below 



Silver Poplar (Populus alba) p.252 



96. Twigs smooth, not at all covered with white felt 97 



97. Twigs yellowish 98 



97. Twigs not yellowish (generally reddish-brown) 99 



98. Lateral buds for the most part divergent, large, about 10 mm. or 

 more in length, tree with more or less pyramidal head, but not 

 narrowly spire-shaped Carolina Poplar (Populus deltoicles) p.260 



98. Lateral buds for the most part appressed, smaller, generally under 



8 mm. long, tree narrowly spire-shaped 



Liombardy Poplar (Populus nigra^ var. italica) p.262 



99. Buds more or less pale dusty-downy 



L.arge-toothe4 Aspen (Populus grandidentata) p.256 



99. Buds not downy 100 



100. Buds large, over 15 mm. long, covered with fragrant sticky gum. 



Balsam Poplar (Populus balsamifera) p.25S 



100. Buds small, under 10 mm. long, shiny, slightly sticky but not 



fragrant Small-toothed Aspen (Populus tremuloides) p.254 



