Pinus banksiana description

Pinus banksiana Lambert 1803

Common Names

Eastern jack, gray, black, black jack, scrub, Prince's or Banksian pine (2); Jack pine, pin gris (3).

Taxonomic notes

Syn: Pinus divaricata (Aiton) Sudworth; P.sylvestris Linnaeus var. divaricata Aiton (3). "In western Alberta and in northeastern British Columbia, it is sympatric with P. contorta and forms hybrid swarms with that species" (3).

Description

"Trees to 27 m; trunk to 0.6 m diam., straight to crooked; crown becoming irregularly rounded or spreading and flattened. Bark orange- to red-brown, scaly. Branches descending to spreading-ascending, poorly self-pruning; twigs slender, orange-red to red-brown, aging gray-brown, rough. Buds ovoid, red-brown, 0.5-1 cm, resinous; scale margins nearly entire. Leaves 2 per fascicle, spreading or ascending, persisting 2-3 years, 2-5 cm x 1-1.5(2) mm, twisted, yellow-green, all surfaces with fine stomatal lines, margins finely serrulate, apex acute to short-subulate; sheath 0.3-0.6 cm, semipersistent. Pollen cones cylindric, 10-15 mm, yellow to orange-brown. Seed cones maturing in 2 years, shedding seeds soon thereafter or often long-serotinous and shedding seeds only through age or fire, upcurved, asymmetric, lanceoloid before opening, ovoid when open, 3-5.5 cm, tan to light brown or greenish yellow, slick, nearly sessile or short-stalked, most apophyses depressed but increasingly mammillate toward outer cone base; umbo central, depressed, small, sunken centrally, unarmed or with a small, reflexed apiculus. Seeds compressed-obovoid, oblique; body 4-5 mm, brown to near black; wing 10-12 mm. 2 n =24. " (3).

Range

In Canada: North West Territories, British Columbia, Alberta, Manitoba, Ontario, Québec, Prince Edward Island, New Brunswick and Nova Scotia; and USA: Minnesota, Wisconsin, Michigan, Illinois, Indiana, Pennsylvania, New York, Vermont, New Hampshire, and Maine. Establishes after fire in boreal forests, tundra transition areas, dry flats and hills, and on sandy soils; at elevations of 0-800 m (3). See also (7).

Big Tree

Diameter 94 cm, height 17 m, crown spread 19 m, located in Lake Bronson, MN (4).

Oldest

Dendrochronology

Ethnobotany

Observations

Remarks

The endangered Kirtland's warbler ( Dendroica kirtlandii ) is dependent on sizable (> 80 ha) stands of young (1.5-4 m tall) P. banksiana forest for breeding habitat. It became endangered due to loss of habitat as fire suppression eliminated young P. banksiana stands from the landscape, and suitable habitat is now maintained (in central Michigan) through an extensive controlled burning program (5, 6). Jack pine is the territorial tree of the North West Territories (3).

Citations

(1) Silba 1986 .
(2) Peattie 1950 .
(3) Robert Kral at the Flora of North America online .
(4) American Forests 1996 .
(5) H.F. Mayfield. 1953. A census of the Kirtland's warbler. The Auk 70: 17-20 (cited in Burns & Honkala 1990 ).
(6) Jack L. Griggs. 1997. All the birds of North America. New York: Harper Collins.

(7) Robert S. Thompson, Katherine H. Anderson and Patrick J. Bartlein. 1999. Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America. U.S. Geological Survey Professional Paper 1650 A&B. URL= http://greenwood.cr.usgs.gov/pub/ppapers/p1650-a/pages/conifers.html , accessed 22-Jan-2000.