View source for Tsuga canadensis

{{SPlantbox
|familia=Pinaceae
|genus=Tsuga
|species=canadensis
|common_name=Canadian hemlock, Eastern hemlock
|name_ref=Flora - A Gardener's Encyclopedia
|habit=tree
|habit_ref=Flora - A Gardener's Encyclopedia
|Min ht box=80
|Min ht metric=ft
|Max ht box=120
|Max ht metric=ft
|height_ref=Flora - A Gardener's Encyclopedia
|Max wd box=30
|Max wd metric=ft
|width_ref=Flora - A Gardener's Encyclopedia
|lifespan=perennial
|exposure=sun
|sun_ref=Flora - A Gardener's Encyclopedia
|features=evergreen
|Temp Metric=°F
|min_zone=4
|usda_ref=Flora - A Gardener's Encyclopedia
|max_zone=9
|image=Tsuga canadensis morton.jpg
|image_width=180
}}
'''''Tsuga canadensis''''', also known as '''Eastern''' or '''Canadian Hemlock''', and in the [[French language in Canada|French-speaking regions]] of Canada as '''Pruche du Canada''', is a [[Pinophyta|coniferous]] [[tree]] native to eastern [[North America]]. It ranges from northeastern [[Minnesota]] eastward through southern [[Quebec]] to [[Nova Scotia]], and south in the [[Appalachian Mountains]] to northern [[Georgia (U.S. state)|Georgia]] and [[Alabama]]. Scattered outlier populations occur in several areas east and west of the Appalachians. It is the [[List of U.S. state trees|state tree]] of [[Pennsylvania]].<ref name=Taylor/>

The eastern hemlock grows well in shade and is very long lived with the oldest recorded specimen being at least 554 years old.<ref name=treering>{{Citation| last =Gove| first =J.H.| author-link =| last2 =Fairweather| first2 =S.E.| author2-link =| title =U.S. Forest Service General Technical Report NC-120| contribution =Tree-ring analysis of a 500-year old hemlock in central Pennsylvania| publisher =| year =1988| pages =483–489| volume =1| edition =| url =| doi =| id =}}</ref>  The tree generally reaches heights of about 31 metres (100 feet),<ref name=Taylor/> but exceptional trees have been recorded up to 53 metres (173 feet).<ref name=usis>{{Citation| last =Blozan| first =Will| author-link =| last2 =| first2 =| author2-link =| title =The Usis Hemlock Climb| date =February 16, 2007| url =http://www.nativetreesociety.org/fieldtrips/gsmnp/usis/usis_hemlock_climb.htm| accessdate = 2007-06-08}}</ref> The diameter of the trunk at breast height is often 1.5 metres (5 feet), but again, outstanding trees have been recorded up to 1.75 meters (6 feet).<ref name=laurel>{{Citation| last =Blozan| first =Will| author-link =| last2 =| first2 =| author2-link =| title =The Laurel Branch Leviathan Climb| date =December 18, 2006| url =http://www.nativetreesociety.org/tsuga/laurel_branch/laurel_branch_leviathan_climb.htm| accessdate =2007-06-08}}</ref> The trunk is usually straight and monopodial, but very rarely is forked.<ref name=farjon/> The crown is broadly conic, while the brownish [[bark]] is scaly and deeply fissured, especially with age.<ref name=Taylor/> The twigs are a yellow-brown in colour with darker red-brown [[pulvinus|pulvini]], and are densely pubescent. The [[bud]]s are ovoid in shape and are very small, measuring only 1.5 to 2.5 mm (0.05 to 0.1 inches) in length. These are usually not resinous, but may be slightly so.<ref name=Taylor/><ref name=farjon/> 

The leaves are typically 15 to 20 mm (0.6 to 0.9 inches) in length, but may be a short as 5 mm (0.2 inches) or as long as 25 mm (1 inch). They are flattened and are typically distichous, or two-ranked. The abaxial surface of the leaf, or underside, is glaucous with 2 broad and clearly visible [[stomata]]l bands, while the adaxial surface, i.e. the upper-side, is a shiny green to yellow-green in colour. The leaf margins are very slightly dentate, or toothed, especially near the apex. The seed [[Conifer cone|cones]] are ovoid in shape and typically measure 1.5 to 2.5 cm (0.6 to 1 inch) in length and 1 to 1.5 cm (0.4 to 0.6 inches) in width. The scales are ovate to cuneate in shape and measure 8 to 12 mm (0.3 to 0.5 inches) in length by 7 to 10 mm (0.3 to 0.4 inches) in width. The apex is more or less rounded and is often projected outward. 24 diploid [[chromosome]]s are present within the tree's [[DNA]].<ref name=Taylor/><ref name=farjon/>

{{Inc|
Tsuga canadensis, Carr. (Abies canadensis, Michx.). Common Hemlock. Tree, attaining 70 and occasionally 100 ft.: young branchlets yellowish brown, pubescent: lvs. linear, obtuse or acutish, dark green and obscurely grooved above, with 2 whitish lines beneath, 1/4 – 2/3 in. long: cones ovoid, 1/2 – 3/4 in. long, peduncled; scales almost orbicular. New Bruns. and Wis., south to Ala.—The hemlock spruce yields the lumber most commonly used in the E. for framing and clap-boarding of buildings. It is not used for finishing lumber. A number of garden forms have been raised; the following are the most important: Var. albo-spica, Nichols. Tips of the young branchlets creamy white. Var. compacta, Senecl. (var. compacta nana, Beissn.). Dwarf conical pyramid with numerous short branchlets clothed with small lvs. Var. globosa, Beissn. (var. globularis erecta, Kunkler). Dense, globose, much-branched form with numerous upright branches nodding at the ends. Var. gracilis, Gord. (var. microphylla, Hort.). Slow-growing form with slender sparingly ramified branches, spreading and more or less drooping at the ends: lvs. very small, about 1/4 in. long. Var. nana, Carr. Dwarf and depressed form with spreading branches and short branchlets. Var. parvifolia, Veitch. Lvs. very small, 1/4 in. long or shorter: branchlets stout, closely set and numerous. Var. pendula, Parsons (var. Sargentii pendula, Hort., var. Sargentiana, Kent). Flat-topped form with spreading branches and drooping branchlets. Very distinct and desirable form.
{{SCH}}
}}

==Cultivation==
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===Propagation===
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===Pests and diseases===
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==Species==
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==Gallery==
<gallery perrow=5>
Image:Tsuga canadensis drawing.png|A line drawing of the leaves and cones from Britton & Brown's 1913 ''Illustrated flora of the northern states and Canada''
Image:Upload.png| photo 1
Image:Upload.png| photo 2
Image:Upload.png| photo 3
</gallery>

==References==
*[[Standard Cyclopedia of Horticulture]], by L. H. Bailey, MacMillan Co., 1963
<!--- xxxxx  *Flora: The Gardener's Bible, by Sean Hogan. Global Book Publishing, 2003. ISBN 0881925381  -->
<!--- xxxxx  *American Horticultural Society: A-Z Encyclopedia of Garden Plants, by Christopher Brickell, Judith D. Zuk. 1996. ISBN 0789419432  -->
<!--- xxxxx  *Sunset National Garden Book. Sunset Books, Inc., 1997. ISBN 0376038608  -->

==External links==
*{{wplink}}

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