Handbook of Treks of Tiir: Xokthf-RN States and Canada. 



13 



The Jack Pine attains its greatest size in 

 the northwestern part of its range, where it is 

 often 70 or 80 ft. in height with trunk 2 nr .{ 

 ft. in diameter, and forms forests of con- 

 siderable extent. Throughout the eastern part 

 of its range, however, it is much less abundant 

 and more reduced in stature, commonly tlirow- 

 ing out its branches immediately above tlie 

 ground as shown in our bark picture. its 

 short needles and small cones incurved upon 

 the branchlets quickly distinguish it from all 

 of its neiglibors. It devolops a ratlier sym- 

 metrical open top of straigtitisli branches and 

 tough llexibh' hnmclilets and its trunk is 

 vested in a dark reddish brown bark rough 

 with irregular scaly plates and ridges. 



The wood, of which a cubic foot when abso- 

 lutely dry weighs 29.67 lbs., is light, soft, not 

 strong, and of a reddish brown color with 

 thick lighter sap-wood. It is used for fuel and 

 occasionallj' for railway ties, posts and lumber. 2 



Leaves in roniot(> clusters of 2, % to I1/2 in. 

 lenj;. stout. si)r(';i(liiii;-. nnjrc nr less curved and dis- 

 tributed aienj; tlie liranclilet, with 12 tiliro-vascular 

 bundles and resin-ducts within tlie pari'ncliyma. 

 FloiC( rs: staniinate yellow, in crowded clusters ; 

 pistillate darlc purple, singly or few togetlier and 

 occasionally clusters on same shoot. Cones small, 

 l%-2 in. lon'^, pointed and strongly incurved, 

 narrow conical-ovoid, ol)lique at base, sessile and 

 scales thickened at apex and furnished with a 

 weak incurved or deciduous |iricl<le : seed rounded, 

 triangular, nearly black and with full wing about 

 >ii in. lotlg and widest near the middle. 



1. Syn. P. Unnksiaiia Lamb. 



2. A. W., IV, 09. 





