32 PINE FAMILY 



Key to species of Pinaster growing in Minnesota, based upon general 

 features — 



1. Leaves more than 1 dm. long 



a. Leaves thin, flexible, bark reddish, native P. resinosa 



b. Leaves thick, stiff, bark gray, cultivate! P. Laricio austriaca 

 2 Leaves less than 1 dm. long 



a. Trees usually 4-20 m. high. 



(1) Leaves flexible, bluegreen, 2.5-7 cm. 



long, cones reflexed, cultivated P. xilrcstris 



(2) Leaves stiff, yellow green, 2.5 to 5.5 



cm. long, cones pointing forward, na- 

 tive P. Banksiana 



b. Low branching shrub, 1-4 m. high, leaves 



4-7 cm. long P. montana 



Pinus Strobus Linne 1753 White Pine 



Large forest tree with a straight trunk up to 40 m. (130 ft.) high, and 

 up to 1 meter in diameter at the base; young trees with regular whorled 

 horizontal branches, the older ones with strong irregular ascending 

 branches forming an open irregular crown ; bark of young tree smooth, 

 greenish gray, very resinous, becoming very thick gray and roughly As- 

 sured ; leaves in fascicles of five, the needles surrounded at first with num- 

 erous scales which soon fall off, leaving them without a scaly sheath, 

 fascicles usually falling at the end of the second year, leaves slender, 

 soft, 7-10 cm. long, triangular in section, minutely serrate; cones woody. 

 cylindrical, stalked, ripening at the end of the second season, 10-15 cm. 

 long, about 3 cm. wide when open, cone scales woody, thin, dark brown 

 when ripe, the exposed parts glossy, seeds winged escaping from the ripe 

 cone : strobus, L. name of some tree. 



In rich often calcareous soil, forming large forests or mixed with de- 

 ciduous trees from Newfoundland and eastern Manitoba south to Iowa, 

 Pennsylvania, and in the mountains to Georgia. In Minnesota through- 

 out the northern and northeastern coniferous forests, also in scattered 

 isolated groves in eastern Minnesota, usually on river bluffs or in sheltered 

 ravines, along the valleys of the St. Croix and Mississippi rivers, and for 

 some distance up some of the tributary valleys. Flowers in May, cones 

 ripe a year from the following September. 



The most valuable timber tree in the state ; wood light brown or red- 

 dish, soft, fine grained, not strong, weight 24 lb. ; used for building con- 

 struction, siding, doors, sash, etc. In cultivation the white pine is orna- 



