UNITED STATES DEPARTMENT OF AGRICULTURE 
Contribution from the Ferest Service 
HENRY S. GRAVES, Forester 
Washington, D. C. PROFESSIONAL PAPER May 22, 1920 
JACK PINE. 
By Witrram Dent StEeRrett, Porest Examiner. 
CONTENTS. 
Page Page. 
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INTRODUCTION. 
Jack pine‘ is a very frugal tree in its climatic and soil requirements. 
The northern limit of its natural range is within 14 degrees of the 
Arctic Circle and the southern is marked by the southern shores of 
Lake Michigan. No other North American pine grows naturally so 
far north and all the others grow farther south. It develops commer- 
cial stands and reproduces itself on dry, barren, sandy ridges and 
plains unsuited to other native trees. The seed germinates more 
quickly and grows more rapidly in its early years on lumbered and 
burned-over forest land and on idle, worn-out, cleared land than the 
other pines occurring within its range. On good soils or on poor soils 
with a cover of moisture-conserving mulch resulting from forest 
srowth it gives way to longer lived species. The fires which are com- 
mon on jack pine lands burn off the litter, keep the soil impoverished, 
1 Jack pine was described under the name of Pinus divaricata by Du Mont de Courset in 1802, and a year 
- later by Lambert as Pinus banksiana (named after Sir Joseph Banks). From the latter are derived the names 
Banksian and Banks pine, by which names the tree is commonly known in Europe and in European 
forestry literature. Lambert’s description of it was from a tree planted in England some time in the eigh- 
teenthcentury. The latter name is more widely used than the former, especially in Europe, but by the law 
of priority in nomenclature P. divaricatais the correctname. The term divaricaia, meaning spreading apart 
or forked, is especially appropriate for jack pine trees growing in the open, The following common 
names are applied to the tree in different parts of the country: Scrub pine, general; gray pine, Vermont, 
Minnesota, and Ontario; jack pine, Lake States and Canada; Princess pine, New Brunswick and Nova 
Scotia; black jack pine, Wisconsin; black pine, Minnesota; cypress, Quebec to Hudson Bay; Canada horn- 
cone pine; check pine (probably a corruption of jack pine); Sir Joseph Banks pine, England; juniper, 
Canada; Banksian pine, European literature; Labrador pine; and Hudson Bay pine. 
140205°—20—-Bull. 820- 
