{{Short description|Species of conifer}} {{Speciesbox | image = Tsuga canadensis morton.jpg | image_caption = Large specimens at [[Morton Arboretum]] | status = NT | status_system = IUCN3.1 | status_ref = <ref name="iucn status 11 November 2021">{{cite iucn |author=Farjon, A. |date=2013 |title=''Tsuga canadensis'' |volume=2013 |article-number=e.T42431A2979676 |doi=10.2305/IUCN.UK.2013-1.RLTS.T42431A2979676.en |access-date=11 November 2021}}</ref> | status2 = G4 | status2_system = TNC | status2_ref = <ref>{{cite web |title=NatureServe Explorer 2.0 |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.131718/Tsuga_canadensis |website=explorer.natureserve.org |access-date=12 April 2022}}</ref> | genus = Tsuga | species = canadensis | authority = ([[Carl Linnaeus|L.]]) [[Élie-Abel Carrière|Carrière]] | range_map = Tsuga canadensis range map 1.png | range_map_caption = Natural range | range_map2 = Tsuga canadensis range map 4.png | range_map2_caption = Closeup view of range }} [[File:Eastern Hemlock Branch 253271179.jpg|thumb|An eastern hemlock branch at the [[Kortright Centre for Conservation]].]] '''''Tsuga canadensis''''', also known as '''Canadian hemlock''',<ref>{{PLANTS|id=TSCA|taxon=Tsuga canadensis|access-date=12 December 2015}}</ref> '''eastern hemlock-spruce''',<ref name=BSBI07>{{BSBI 2007 |access-date=2014-10-17 }}</ref> or '''eastern hemlock''', and in the French-speaking regions of Canada as '''''pruche du Canada''''', is a [[Pinophyta|coniferous]] [[tree]] [[native plant|native]] to eastern North America. It is the [[List of U.S. state trees|state tree]] of Pennsylvania.<ref name=Taylor /> Eastern hemlocks are widespread throughout much of the [[Great Lakes region]], the [[Appalachian Mountains]], [[The Maritimes]] and the [[Northeastern United States]]. They have been introduced in the [[United Kingdom]] and mainland Europe, where they are used as ornamental trees.
Eastern hemlock populations in North America are threatened in much of their range by the spread of the invasive [[Hemlock woolly adelgid]], which infests and eventually kills trees. Declines in population from hemlock wooly adelgid infestation have led to ''Tsuga canadensis'' being listed as Near Threatened on the [[IUCN Red List]].
Eastern hemlocks are long lived trees, with many examples living for more than 500 years. They can grow to heights of more than {{Convert|100|ft|m|order=flip}}, and are tolerant of shade, moist soil, and slopes. Hemlock wood is used in construction, and for [[railroad tie]]s. Historically its bark was an important source of [[tannin]] for the leather [[Tanning (leather)|tanning]] industry.<ref>{{Cite web|last=Godman|first=R. M.|title=Eastern Hemlock|url=https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/tsuga/canadensis.htm|access-date=2021-12-13|website=www.srs.fs.usda.gov}}</ref> Eastern hemlocks are popular as ornamental trees, thanks to their tolerance of a wide variety of soil and light conditions, as well as their characteristic drooping branches of the mutated tree known as 'weeping hemlock'.
== Description == [[File:Tsuga canadensis drawing.png|left|upright=0.9|thumb|A line drawing of the leaves and cones from Britton and Brown's 1913 ''Illustrated flora of the northern states and Canada'']] The eastern hemlock grows well in shade and is very long lived, with the oldest recorded specimen, found in [[Tionesta, Pennsylvania]], being at least 554 years old.<ref name=treering>{{Citation| last1 =Gove| first1 =J.H.| last2 =Fairweather| first2 =S.E.| title =U.S. Forest Service General Technical Report NC-120| contribution =Tree-ring analysis of a 500-year old hemlock in central Pennsylvania| year =1988| pages =483–489| volume =1|mode =cs1}}</ref> The tree generally reaches heights of about {{cvt|31|m|ft|0|sp=us}},<ref name=Taylor /> but exceptional trees have been recorded up to {{cvt|53|m|ft|sp=us}}.<ref name=usis>{{Citation| last =Blozan| first =Will| title =The Usis Hemlock Climb| date =February 16, 2007| url =http://www.nativetreesociety.org/fieldtrips/gsmnp/usis/usis_hemlock_climb.htm| access-date = 2007-06-08 |mode =cs1}}</ref> The diameter of the trunk at breast height is often {{cvt|1.5|m|ftin}}, but again, outstanding trees have been recorded up to {{cvt|1.75|m|ftin}}.<ref name=laurel>{{Citation| last =Blozan| first =Will| title =The Laurel Branch Leviathan Climb| date =December 18, 2006| url =http://www.nativetreesociety.org/tsuga/laurel_branch/laurel_branch_leviathan_climb.htm| access-date =2007-06-08 |mode =cs1}}</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 (botany)|bark]] is scaly and deeply fissured, especially with age.<ref name=Taylor /> The twigs are a yellow-brown in color with darker red-brown [[pulvinus|pulvini]], and are densely pubescent. The [[bud]]s are ovoid in shape and are very small, measuring only {{cvt|1.5|to|2.5|mm|in|frac=8}} in length. These are usually not resinous, but may be slightly so.<ref name=Taylor /><ref name=farjon />
The leaves are typically {{cvt|15|to|20|mm|in}} in length, but may be as short as {{cvt|5|mm|in}} or as long as {{cvt|25|mm|in|frac=8}}.The leaves are arranged on little stalks, a characteristic that does not appear in the other evergreen trees.<ref>{{Cite web |title=Studies of Trees |url=https://www.gutenberg.org/cache/epub/16116/pg16116-images.html#ch_i-iii}}</ref> They are flattened and are typically distichous, or two-ranked. The bottom of the leaf is glaucous with two broad and clearly visible [[stomata]]l bands, while the top is a shiny green to yellow-green in color. The leaf margins are very slightly toothed, especially near the apex. The seed [[Conifer cone|cones]] are ovoid in shape and typically measure {{cvt|1.5|to|2.5|cm|in|frac=8}} in length and {{cvt|1.0|to|1.5|cm|in|frac=8}} in width. The scales are ovate to cuneate in shape and measure {{cvt|8|to|12|mm|in|frac=8}} in length by {{cvt|7.0|to|10|mm|in|frac=8}} in width. The apex is more or less rounded and is often projected outward. Twenty-four diploid [[chromosome]]s are present within the trees' [[DNA]].<ref name=Taylor /><ref name=farjon />
== Wood == The wood is soft, coarse-grained, and light buff in color. Air-dried, {{one2a|{{convert|1|cuft|spell=in}}}} weighs {{convert|28|lb}}. The lumber is used for general construction and crates. Because of its unusual power of holding spikes, it is also used for railroad ties. Untreated, the wood is not durable if exposed to the elements. As a fuel, it is low in value. The wood is also a source of pulp for paper manufacturing.<ref>Collingwood, C.H. and Warren D. Brush (Revised and Edited by Devereux Butcher). 1974. ''Knowing Your Trees''. American Forestry Association. Washington, District of Columbia. 374 pp. ("EASTERN HEMLOCK", pp. 88-89.)</ref>
== Distribution and habitat == [[File:Stand of Eastern Hemlock and White Pine in Tiadaghton State Forest, Pennsylvania.jpg|thumb|Stand of eastern hemlock and [[eastern white pine]] in [[Tiadaghton State Forest]], Pennsylvania; note the hemlocks' deeply fissured bark]] ''T. canadensis'' occurs at sea level in the north of its distribution,<ref name=farjon /> but is found primarily at elevations of {{cvt|600|-|1800|m|ft}}. It ranges from northeastern [[Minnesota]] eastward through southern [[Quebec]] and into [[Nova Scotia]], and south in the [[Appalachian Mountains]] to northern [[Georgia (U.S. state)|Georgia]] and Alabama.<ref name=Taylor /><ref>{{Cite news|url=http://www.treesearch.fs.fed.us/pubs/50590|title=Eastern hemlock found in Macon County, Alabama|last=South|first=David B.|date=2016}}</ref> Disjunct populations occur in the [[Piedmont (United States)|Piedmont region]], northern Alabama, western [[Ohio]] and into [[Indiana]], as well as western Wisconsin and eastern Minnesota.<ref name=farjon>Farjon, A. (1990). ''Pinaceae. Drawings and Descriptions of the Genera''. Koeltz Scientific Books {{ISBN|3-87429-298-3}}.</ref><ref name=thompson>{{citation| author = Thompson, Robert S.| author2 = Anderson, Katherine H.| author3 = Bartlein, Patrick J.| contribution=Tsuga canadensis| year=1999| title=Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America| page = 1| publisher=[[U.S. Geological Survey]]| doi = 10.3133/pp1650AB| bibcode = 1999usgs.rept....1T| url=https://pubs.usgs.gov/pp/p1650-a/pages/tscatrim.pdf| access-date=2007-07-05 |mode=cs1}}</ref> In Canada, it is present in Ontario and all provinces to the east except Newfoundland and Labrador.<ref name=Taylor>{{eFloras|last =Taylor| first =Ronald J.|1|233501320|Tsuga canadensis}}</ref> Its range completely overlaps that of the closely related ''[[Tsuga caroliniana]]''.<ref name=USDF />
It is found primarily on rocky ridges, ravines, and hillsides with relatively high levels of moisture.<ref name=Taylor />
=== Climate === Eastern hemlock is generally confined to areas with highland climates, with cool and humid conditions. Precipitation in the areas where it grows is typically {{cvt|740|mm|in}} to more than {{cvt|1270|mm|in}} per year. The lower number is more typical of northern forests that receive heavy snowfall; the higher number is common in southerly areas with high summer rainfall. Near the Atlantic coast and in the southern Appalachians where the trees often reach their greatest heights, annual rainfall often exceeds {{cvt|1520|mm|in}}. In the north of its range, the temperatures in January average {{convert|-12|C}}, while in July they average only {{convert|16|C}}. In these areas, the frost-free season can last fewer than 80 days. In contrast, the southern end of the range experiences up to 200 days without frost and January temperatures as high as {{convert|6|C}}.<ref name=USDF>{{Silvics | last =Godman | first = R. M. | last2 = Lancaster | first2 = Kenneth | genus = Tsuga | species = canadensis | volume = 1 | access-date =2007-07-05}}</ref> [[File:Hemlock's deciduous nature.jpg|thumb|left|Hemlock boughs in the autumn, shedding older foliage]] [[File:Eastern Hemlocks, Fairfax, VA.jpg|thumb|Old hemlocks, Fairfax County, VA]]
== Hemlock woolly adelgid == [[File:Tsuga canadensis adelges.jpg|thumb|Shoot infested with [[hemlock woolly adelgid]]]] The species is currently threatened by the [[hemlock woolly adelgid]] (''Adelges tsugae''), a sap-sucking [[Hemiptera|bug]] introduced from [[East Asia]] to the United States in 1924, and first found in the native range of eastern hemlock in the late 1960s.<ref>{{Citation |last1=McClure |first1=M. S. |year=1987 |title=Biology and control of hemlock woolly adelgid |journal=Bulletin of the Connecticut Agricultural Experiment Station |volume=851 |pages=1–9 |url=http://ddr.nal.usda.gov/bitstream/10113/1607/1/IND43803867.pdf |archive-url=https://web.archive.org/web/20120425091352/http://ddr.nal.usda.gov/bitstream/10113/1607/1/IND43803867.pdf |archive-date=April 25, 2012 |access-date=October 24, 2011 |mode=cs1}}</ref> The adelgid has spread very rapidly in southern parts of the range once becoming established, while its expansion northward is much slower.<ref>{{Cite journal |last1=Paradis |first1=Annie |last2=Elkinton |first2=Joe |last3=Hayhoe |first3=Kathrine |last4=Buonaccorsi |first4=John |date=2008-06-01 |title=Role of winter temperature and climate change on the survival and future range expansion of the hemlock woolly adelgid (Adelges tsugae) in eastern North America |url=https://link.springer.com/article/10.1007/s11027-007-9127-0 |journal=Mitigation and Adaptation Strategies for Global Change |language=en |volume=13 |issue=5 |pages=541–554 |doi=10.1007/s11027-007-9127-0 |bibcode=2008MASGC..13..541P |issn=1573-1596|url-access=subscription }}</ref> Virtually all the hemlocks in the southern Appalachian Mountains have seen infestations of the insect within the last five to seven years, with thousands of hectares of stands dying within the last two to three years.{{when|date=April 2026}}<ref>{{Cite journal |last1=Vose |first1=James M. |last2=Wear |first2=David N. |last3=Mayfield |first3=Albert E. |last4=Dana Nelson |first4=C. |date=2013-03-01 |title=Hemlock woolly adelgid in the southern Appalachians: Control strategies, ecological impacts, and potential management responses |url=https://www.sciencedirect.com/science/article/abs/pii/S0378112712006615 |journal=Forest Ecology and Management |volume=291 |pages=209–219 |doi=10.1016/j.foreco.2012.11.002 |bibcode=2013ForEM.291..209V |issn=0378-1127|url-access=subscription }}</ref> Attempts to save representative examples on both public and private lands are on-going. A project named "Tsuga Search", funded by the [[Great Smoky Mountains National Park]], is being conducted to save the largest and tallest remaining eastern hemlocks in the Park. Through Tsuga Search, hemlocks have been found with trunk volumes up to 44.8 m<sup>3</sup> within the park,<ref name=gd /> making it the largest eastern evergreen conifer, eclipsing in volume both eastern white pine (''Pinus strobus'') and [[Loblolly Pine|loblolly pine]] (''Pinus taeda''). The tree is currently listed as a [[near threatened]] species in the [[IUCN Red List]], but this is based largely on its wide distribution and because the adelgid populations have not reached the northern areas of its range.<ref name="iucn status 11 November 2021" /> In 2018, [[Kejimkujik National Park]], in [[Nova Scotia]], became the first [[National parks of Canada|National Park of Canada]] to detect hemlock woolly adelgid within its boundaries.<ref>{{Cite web |last=Parks Canada Agency |first=Government of Canada |date=2026-01-16 |title=Protecting Eastern hemlock in Kejimkujik |url=https://parks.canada.ca/pn-np/ns/kejimkujik/nature/conservation/hwa-report |access-date=2026-02-17 |website=parks.canada.ca}}</ref> Since then, park staff have been implementing active management options to preserve several hemlock stands within the park.<ref>{{Cite web |last=Impact Assessment Agency of Canada |title=Active Management of Hemlock Woolly Adelgid in Kejimkujik National Park and National Historic Site |url=https://www.iaac-aeic.gc.ca/050/evaluations/proj/82824?culture=en-CA |archive-url=http://web.archive.org/web/20220915093118/https://www.iaac-aeic.gc.ca/050/evaluations/proj/82824?culture=en-CA |archive-date=2022-09-15 |access-date=2026-02-17 |website=iaac-aeic.gc.ca |language=en}}</ref>
A study in 2009 conducted by scientists with the [[U.S. Forest Service]] [[Southern Research Station]] suggests the hemlock woolly adelgid is killing hemlock trees faster than expected in the southern Appalachians, and rapidly altering the [[carbon cycle]] of these forests. According to ''[[Science Daily]]'', the pest could kill most of the region's hemlock trees within the next decade.{{update inline |reason=It's been more than a decade|date=December 2019}} According to the study, researchers found "hemlock woolly adelgid infestation is rapidly impacting the carbon cycle in [hemlock] tree stands," and "adelgid-infested hemlock trees in the South are declining much faster than the reported 9-year decline of some infested hemlock trees in the Northeast."<ref name=scid311>[https://www.sciencedaily.com/releases/2009/02/090226122730.htm Hemlock Trees Dying Rapidly, Affecting Forest Carbon Cycle]</ref>
[[File:TsugaCanadensisBark.jpg|thumb|upright|Closeup of bark]] In a 2009 case study, [[entomology|entomologists]] from the U.S. Forest Service, [[Cornell University]], and the [[University of Massachusetts-Amherst]] released 900 ''[[Laricobius nigrinus]]'' beetles into a stand of adelgid-infested hemlocks near [[Lansing, New York]]. ''L. nigrinus'', which is native to the Pacific Northwest, naturally preys on the hemlock wooly adelgid. The particular site near Lansing was chosen because its hemlocks are only lightly infested with the woolly adelgid, and enough trees are found to sustain a long-term study. The site will be left untreated with pesticides for 10 years to study how well the ''L. nigrinus'' beetles become established; if the experiment proves successful, researchers expect the population will take two to three years to build to levels where they can be readily detected.<ref name=scidaily111909>[https://www.sciencedaily.com/releases/2009/11/091113124302.htm Predator Beetle to Battle Hemlock Pest]</ref>
==Ecology== The tree can be found living in association with many forest mushrooms, such as ''[[Ramaria flavosaponaria]]''<ref name="Petersen">{{cite journal |last1=Petersen |first1=Ronald H. |author-link1=Ron Petersen |title=Notes on Clavarioid Fungi. XX. New Taxa and Distributional Records in ''Clavulina'' and ''Ramaria'' |journal=Mycologia |date=November 1985 |volume=77 |issue=6 |pages=903–919 |doi=10.2307/3793302 |language=en |issn=0027-5514 |oclc=7377077277|jstor=3793302 }}</ref> and [[Ganoderma tsugae]] (which has the common name hemlock varnish shelf.)<ref>{{Cite web |title=Ganoderma tsugae (MushroomExpert.Com) |url=https://www.mushroomexpert.com/ganoderma_tsugae.html#:~:text=Ganoderma%20tsugae%20(MushroomExpert.Com)&text=This%20incredible%20mushroom%20is%20found,east%20of%20the%20Rocky%20Mountains. |access-date=2026-02-17 |website=www.mushroomexpert.com}}</ref>
== Paleoecology == The mid-[[Holocene]] decline of hemlock populations is a much-studied phenomenon.<ref name=Oswald>{{cite journal|last=Oswald|first=W. W.|author2=Foster, D. R. |title=Middle-Holocene dynamics of Tsuga canadensis (eastern hemlock) in northern New England, USA|journal=The Holocene|date=8 August 2011|volume=22|issue=1|pages=71–78|doi=10.1177/0959683611409774|s2cid=42106379|url=http://harvardforest.fas.harvard.edu/sites/harvardforest.fas.harvard.edu/files/publications/pdfs/Oswald_Holocene_2011.pdf|access-date=6 March 2013}}</ref> From its foundation in the early Holocene (around 16,000 BP) in what is now the southeastern US, ''T. canadensis'' expanded rapidly and successfully into its potential range.<ref name=Delcourt>{{cite book|last=Delcourt|first=Hazel R.|title=Quaternary Ecology: a Paleoecological Perspective|year=1991|publisher=Chapman and Hall|location=London|isbn=978-0-412-29790-8|pages=[https://archive.org/details/quaternaryecolog0000delc/page/43 43–44]|edition=1st|author2=Delcourt, Paul A.|url=https://archive.org/details/quaternaryecolog0000delc/page/43}}</ref> However, [[Palynology|palynological]] analyses show the hemlock population experienced a pronounced decline approximately 5,500 BP that lasted for about 1,000 years. Continued research points to other, though less dramatic, dips in Holocene hemlock populations.<ref name=Oswald /><ref name=Zhao>{{cite journal|last=Zhao|first=Yan|author2=Yu, Zicheng |author3=Zhao, Cheng |title=Hemlock (Tsuga canadensis) declines at 9800 and 5300 cal. yr BP caused by Holocene climatic shifts in northeastern North America|journal=The Holocene|date=23 April 2010|volume=20|issue=6|pages=877–886|doi=10.1177/0959683610365932|bibcode=2010Holoc..20..877Z|s2cid=220988296 }}</ref> Pathogens, insects, and climatic change, and a combination of these, have all been proposed to explain these anomalies. The eastern hemlock increased again after the major decline, but did not recover its former place as a dominant species.
== Exceptional trees == Due to it being a long-lived tree, several very large or otherwise impressive trees exist along the east coast of North America. One organization, the Eastern Native Tree Society (ENTS), has been particularly active in discovering and measuring these trees. In the southern Appalachians, many individuals reach {{convert|45|m}} tall, and one tree has been measured in the Great Smoky Mountains National Park to {{cvt|52.8|m|ftin}} tall, though this tree is now dead from hemlock woolly adelgids; the tallest now surviving, the "Noland Mountain tree", is {{cvt|51.8|m|ftin}} tall.<ref name=gd /> Altogether, ENTS has confirmed four trees to heights of {{cvt|51|m}} or more by climb and tape drop. In the Northeast, the tallest accurately measured tree is {{cvt|44|m}}. This tree, named the Seneca hemlock, grows in Cook Forest State Park, PA. Above 43°N latitude, the maximum height of the species is less, under {{cvt|39|m}}. In New England, ENTS has measured hemlocks to {{cvt|42|m}}, although trees above {{cvt|39|m}} are extremely rare in New England. By 44°N, the maximum height is probably not more than {{cvt|35|m}}. Diameters of mature hemlocks range from {{cvt|0.75|–|1.8|m|ftin}}, with trees over {{cvt|1.6|m|ftin}} in diameter being very rare. In New England, the maximum diameter is {{cvt|1.4|m|ftin}}.
Trunk volume is the third dimension to receive attention by ENTS. Many eastern hemlocks have been modeled to over {{cvt|30|m3}} trunk volume, and the largest has been calculated to be {{cvt|44.8|m3}},<ref name=gd>{{Gymnosperm Database |family=Pinaceae |genus=Tsuga |species=canadensis}}</ref> making it the largest natural evergreen conifer in the eastern United States. The center of maximum size development for the species is the southern Appalachians, especially the Great Smoky Mountains.
== Cultivation == ''Tsuga canadensis'' has long been a popular tree in cultivation. The tree's preference for partial shade and tolerance of full shade allows it to be planted in areas where other conifers would not easily grow. In addition, its very fine-textured foliage that droops to the ground, its pyramidal growth habit, and its ability to withstand hard pruning make it a desirable [[ornamental plant|ornamental tree]]. In cultivation, it prefers sites that are slightly acidic to neutral with nutrient-rich and moist but well-drained soil. It is most often used as a specimen, for a screen, or in small group plantings, though it can also be trained as a dense formal hedge. It should not be used on roadsides where salt is used in winter, as its foliage is sensitive to salt spray. It is also poorly adapted as a windbreak tree, as wind exposure causes dieback in winter. It has several drawbacks, such as a fairly low tolerance of urban stress, intolerance for very wet or very dry soils, and susceptibility to attack by the hemlock woolly adelgid, though this is treatable.<ref name=UConn /> Its tendency to shed needles rapidly after being cut down renders it unsuitable as a [[Christmas tree]].
It was introduced to British gardens in 1736.<ref name=afm>Mitchell, A. F. (1974). ''A Field Guide to the Trees of Britain and Northern Europe''. Collins {{ISBN|0-00-212035-6}}</ref> In the [[UK]], it is encountered frequently in gardens both large and small, as well as some parks, and is most common in the eastern areas of the country. It is sometimes employed as a [[hedge (barrier)|hedge]], but is considered inferior for this usage compared to ''[[Tsuga heterophylla]]'' (western hemlock); it is not well adapted to the UK climate and as a consequence often has a poorly developed, forked and sinuous trunk there.<ref name=afm /><ref name=afm2>Mitchell, A. F. (1972). ''Conifers in the British Isles''. Forestry Commission Booklet 33.</ref> In [[Germany]], it is the most frequently seen hemlock in cultivation, and is also used in [[forestry]].<ref name=schmeil>{{in lang|de}} Schmeil, O., Fitschen, J., & Seybold, S. (2006). ''Flora von Deutschland'' 93. Auflage, p. 424. Quelle & Meyer Verlag, Wiebelsheim. {{ISBN|3-494-01413-2}}.</ref>
=== Cultivars === [[File:Img tsuga canadensis sargentii 1891.jpg|right|upright=1.13|thumb|The weeping shrub form ''T. canadensis'' 'Sargentii']] Over 300 [[cultivar]]s have been selected for use, many of them being dwarf forms and shrubs. A partial list of popular cultivars includes:<ref name=UConn>{{cite web|title=Tsuga canadensis|url=http://www.hort.uconn.edu/plants/t/tsucan/tsucan1.html|work=UConn Plant Database|publisher=University of Connecticut|access-date=19 August 2013}}</ref><ref>Welch, H., & Haddow, G. (1993). ''The World Checklist of Conifers''. Landsman's. {{ISBN|0-900513-09-8}}.</ref> *'Beehive' – a very small dwarf shrub typically growing to {{cvt|1|m}} high and 1.5 m wide, resembling a spreading beehive in form *'Bennett' – a dwarf shrub reaching {{cvt|1|m}} high and {{cvt|1.5|m}} wide, with upper branchlets that first ascend and then arch upper, this selection prefers partial shade. *'Cole's Prostrate' – a [[groundcover]] form that can also be used in [[bonsai]] as an alternative to the prostrate [[juniper]]s, it slowly grows to only {{cvt|30|cm}} tall with a {{convert|1.3|m|ft|adj=on}} spread, with the central stems eventually becoming visible. It also prefers partial shade. *'Gentsch White' – a dwarf shrub growing to {{cvt|1.3|m}} tall with an equal spread and new spring growth that turns creamy-white in autumn through winter, creating a dramatic contrast with the dark green old growth, it is easily scorched by the sun and requires partial shade. It is recommend to feather shear annually to keep it compact and create more tip growth. *'Jeddeloh' – a dwarf shrub reaching to {{cvt|1|m}} high and {{cvt|1.5|m}} wide, showing a small concavity in the centre, it is an alternative to the bird's-nest spruce (''[[Picea abies]]'' 'Nidiformis'). This cultivar has gained the [[Royal Horticultural Society]]'s [[Award of Garden Merit]].<ref name=rhs>{{cite web|title=Tsuga canadensis 'Jeddeloh' | url = https://www.rhs.org.uk/Plants/54156/Tsuga-canadensis-Jeddeloh/Details|publisher=Royal Horticultural Society|access-date=13 March 2021}}</ref> *'Pendula' – an upright weeping form whose height is dependent on how long it is staked, but is typically seen {{cvt|0.6|–|1.5|m}} tall with a {{convert|1.5|m|ft|adj=on}} spread. It has also won the AGM.<ref>{{cite web | url = https://www.rhs.org.uk/Plants/54156/Tsuga-canadensis-Jeddeloh/Details | title = ''Tsuga canadensis'' 'Pendula' | publisher = RHS | access-date = 5 March 2021}}</ref> *'Sargentii' – a popular large weeping shrub that grows to {{cvt|3|m}} tall with a wide spread up to {{cvt|6|m}}, it features numerous pendulous branches and is most effectively employed near water, in rock gardens, or on embankments.
==Uses== American pioneers made tea from the tree's leafy twigs and used its branches as brooms.<ref>{{cite book|last=Little|first=Elbert L.|title=The Audubon Society Field Guide to North American Trees: Eastern Region|publisher=Knopf|location=New York|year=1980|isbn=0-394-50760-6|page=300}}</ref> Tea can be made from the needles. The inner bark, which is best in winter and coming into spring, can be eaten raw or boiled; it can also be used to make flour.<ref>{{Cite book|last1=Elias|first1=Thomas S.|title=Edible Wild Plants: A North American Field Guide to Over 200 Natural Foods|last2=Dykeman|first2=Peter A.|publisher=[[Sterling Publishing|Sterling]]|year=2009|isbn=978-1-4027-6715-9|location=New York|page=122|oclc=244766414|orig-date=1982}}</ref>
== In popular culture ==
* Numerous place names in North America are named Hemlock. For a list, see [[Hemlock (disambiguation)|Hemlock]]. * Hemlocks are a recurring image in the novel ''[[Ethan Frome]]''. Author Edith Wharton described "hemlock boughs bent inward to their trunks by the weight of the snow," "intensely blue shadows of hemlocks on sunlit snow," and darkness "dropping down like a black veil from the heavy hemlock boughs."<ref>{{Cite web |last=Wharton |first=Edith |title=Ethan Frome |url=https://www.gutenberg.org/cache/epub/4517/pg4517-images.html |access-date=2024-09-18 |website=Project Gutenberg |language=en}}</ref>
==References== {{Reflist|2}}
==External links== *[http://www.cas.vanderbilt.edu/bioimages/species/frame/tsca.htm ''Tsuga canadensis'' images at bioimages.vanderbilt.edu] *[http://www.nativetreesociety.org/tsuga/index_tsuga_search.htm Eastern Native Tree Society's Tsuga Search Project]
{{Taxonbar|from=Q1137143}} {{Authority control}}
[[Category:Tsuga|canadensis]] [[Category:Hardwood forest plants]] [[Category:Trees of Northern America]] [[Category:Flora of the Appalachian Mountains]] [[Category:Symbols of Pennsylvania]] [[Category:Trees of humid continental climate]] [[Category:Natural history of the Great Smoky Mountains]] [[Category:Garden plants of North America]] [[Category:Ornamental trees]] [[Category:Plants described in 1763]]