PICEA ^^ 



bark broken into flaky gray or reddish scales; branchlets pubescent; 

 leaves short and thick, mostly 6-10 mm. long, pale bluish-green 

 with a white bloom; cones short-ovoid or globose, 2-3 cm. long, 

 dull grayish-brown, the scales erose. Cool slopes and bogs, Lab- 

 rador to Alaska, south to Alberta and Pennsylvania, with scatter- 

 ed colonies in the mountains of Virginia; typically a Canadian 

 tree (Fig. 6). 



4. _P^ abies (L. ) Karst. Norway Spruce . (P. excelsa Link). 

 A tree to 50 m. high, with drooping lower branches; bark reddish- 

 brown; buds reddish or light brown, not resinous; branchlets near- 

 ly glabrous; leaves slender, sharp-pointed, dark-green, glossy; 

 cones 1-1. 5 dm. long. Introduced from Europe as a shade tree, 

 spreading slightly from cultivation in the northern section(Fig. 7). 



LARK Mill. (Pinaceae) 



Trees with horizontal or ascending branches and small de- 

 ciduous leaves, mostly clustered at the ends of short stubby 

 branchlets. Cones ovoid or cylindric, small, erect, the scales 

 thin, persistent. 



1. JL. laricina (Du Roi) K. Koch. Larch. Tamarack. A slen- 

 der tree 10-20 m. high, 3-6 dm. in diameter, the branches spread- 

 ing; bark thin, roughened with small, rounded, red -brown scales; 

 twigs slender, orange, pith minute, brown, roundish; buds soli- 

 tary, sessile, globose or short-ovoid, with numerous brown scales; 

 leaf-scars minute, alternate, raised on decurrent bases, mostly 

 closely clustered on spurs that elongate very slowly; bundle-trace 

 1; stipule-scars none; cones less than 2 cm. long, persistent into 

 winter. Labrador to Alaska, south mostly in swamps to Minnesota 

 and the mountains of West Virginia (Fig. 8). 



PINUS L. (Pinaceae) 



Evergreen trees with 2 kinds of leaves, the primary ones 

 solitary, scalelike, deciduous the first year, the secondary form- 

 ing the ordinary foliage, narrowly linear, arising in the axils of 

 the primary in bundles (fascicles ) of 2 to 5, persistent for several 

 years. Cones requiring 2 years for ripening, those of the first year 

 small and green in winter, maturing the second autumn but often 

 persisting for several years, usually armed with prickles or 

 spines. 



a. Leaves 5 in a fascicle 1. P. strobus 



a. Leaves 2 or 3 in a fascicle 



b. Leaves 3 in a fascicle 7. P. rigida 



