PINACEAE 

 Jack Pine. Scrub Pine 



Pinus banksiana, Lamb. [Pinus divaricata, (Ait.} 

 DuMont de Cours] 



HABIT. Usually a small tree 20-30 feet 'high, with a trunk 

 diameter of 8-12 inches ; forming a crown varying from open and 

 symmetrical to scrubby, stunted, and variously distorted. 



LEAVES. In clusters of two; about i inch long; narrow- 

 linear, with sharp-pointed apex; stout, curved or twisted, diver-, 

 gent from a short sheath ; dark gray-green. Persistent 2-3 years. 



FLOWERS. May- June ; monoecious ; the staminate in ob- 

 long clusters */ 2 inch long, composed of many sessile, yellow 

 anthers imbricated upon a 'central axis; the pistillate in sub- 

 globose clusters, composed of many carpel-like, purple scales 

 (subtended by small bracts) spirally arranged upon a central axis. 



FRUIT. Autumn o'f second or third season, but remaining 

 closed for several years and persistent on the tree for 10-15 years ; 

 erect, usually incurved, oblong-conical, sessile cones, i l / 2 -2 

 inches long ; scales thickened at the apex ; seeds triangular, nearly 

 black, y% inch long, with wings Yz inch long. 



WINTER-BUDS. Terminal bud J4 inch long, ovoid, 

 rounded, pale brown; lateral buds smaller. 



BARK. Twigs yellow-green, becoming purple, finally dark 

 red-brown and rough with the persistent bases of fallen leaves; 

 thin, dark red j brown on the trunk, with shallow, rounded ridges, 

 rough-scaly on the surface. 



WOOD. Light, soft, weak, close-grained, light brown, with 

 thick, whitish sap wood. 



DISTRIBUTION. Common from Clare County northward ; 

 occurs sparingly along the lake shore as far south as Grand 

 Haven on the west and Port Austin on the east. 



HABITAT. Sandy, sterile -soil. 



NOTES. Cones open unevenly. Slow of growth. Difficult 

 to transplant. 



