138 TREES OF MINNESOTA. 



Pinus divaricata. ( P. banksiana. ) Jack Pine. Nor- 

 thern Scrub Pine. Gray Pine. 



Leaves in twos, short, from f to 1| inches long, acute, 

 rig-id, thick, more or less curved and twisted, falling- the 

 second or third season; inner side channeled; margins very 

 minutely serrate, sheaths short; buds very resinous. Cones 

 ovoid acuminate, about 2 inches long, often curved, laterally 

 located on branchlets, often in pairs. They are generally 

 opened by the sun, but where they are in the shade they will 

 remain on the trees unopened for several years until they be- 

 come deeply covered with moss and sometimes until over- 

 grown and imbedded in the wood and bark. The seeds are 

 about i of an inch long with 4 to 5 cotyledons. Those from 

 the old cones seem to grow as readily as fresh seeds when 

 sown. A very pronounced peculiarity of this tree is the habit 

 of forming several whorls of branches on the new growth. 

 This is especially noticeable when the trees are young and 

 growing rapidly when as many as six whorls of branches may 

 be seen on a year's growth. This tree under favorable con- 

 ditions will occasionally attain a height of 125 feet and a 

 diameter of 2 feet. However, it is seldom over 70 feet high 

 and 8 to 12 inches in diameter and generally where it occurs 

 in pine forests it is only 40 or 50 feet high. 



Distribution. It is distributed from northern New England 

 and the Valley of the St. Lawrence westward along our 

 northern frontier to the Rocky Mountains and north to the 

 Arctic Circle; found growing in sandy land and land that has 

 been recently severely burned. It covers large areas of poor 

 sandy lands in Minnesota. In this state it probably has 

 about the same range as Norway Pine. 



Propagation. By seeds. The cones may -be obtained at 

 any season of the year and kept out of doors until spring, 

 when they can be opened by the application of a little heat. 

 The seeds from the old cones seem to have as much vitality 

 as those from young cones. In the woods the cones of Jack 

 Pine often remain closed until a fire sweeping over the land 

 causes them to open and allows the seeds to fall in the loose 

 ashes, where they soon start into growth. On account of this 

 peculiarity it is sometimes called the Fire Pine. The seed- 



