Tsuga canadensis (Canadian Hemlock)

Interesting Facts

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Numerous cultivars of Tsuga canadensis have been developed, including compact shrubs , dwarfs , and graceful trees . Wood of the species tends to be brittle and inferior to that of the other North American hemlocks. [source]
Eastern hemlock ( Tsuga canadensis ) is the state tree of Pennsylvania. [source]
Native Americans used the inner bark , roots , and needles of the Eastern Hemlock in antiseptics , cold medicines, and remedies for rheumatism and arthritis. In times of famine, they ate the inner bark. Its soft, lightweight wood makes lousy firewood, but it does work well in crates, general construction, and paper pulp. Tannins in the tree's bark soften leather .
This native evergreen also helps wildlife. It provides protective cover . Deer and rabbits eat its lacy needles, birds such as Chickadees, and small mammals enjoy the small seeds inside the tiny cones, and porcupines chew its inner bark.
Today, this stately 50-80' tall tree thrives in moist, shady, north facing locations. Eastern Hemlocks can live up to 1,000 years, unless they succumb to the hemlock wooly adelgid, an introduced pest that affects hemlock forests throughout the eastern U.S.
Native Americans used the inner bark, roots, and needles of the Eastern Hemlock in antiseptics, cold medicines, and remedies for rheumatism and arthritis. In times of famine, they ate the inner bark. Its soft, lightweight wood makes lousy firewood, but it does work well in crates, general construction, and paper pulp. Tannins in the tree's bark soften leather.
This native evergreen also helps wildlife. It provides protective cover. Deer and rabbits eat its lacy needles, birds such as Chickadees, and small mammals enjoy the small seeds inside the tiny cones, and porcupines chew its inner bark.
Today, this stately 50-80' tall tree thrives in moist, shady, north facing locations. Eastern Hemlocks can live up to 1,000 years, unless they succumb to the hemlock wooly adelgid, an introduced pest that affects hemlock forests throughout the eastern U.S.

Common Names

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Click on the language to view common names.

Common Names in English:

Canadian Hemlock, Eastern Hemlock, Hemlock

Common Names in French:

Pruche De L´est, Pruche Du Canada

Common Names in German:

Hemlocktanne

Description

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Family Pinaceae

Trees or rarely shrubs , evergreen or deciduous, monoecious. Branchlets often dimorphic : long branchlets with clearly spirally arranged , sometimes scalelike leaves; short branchlets often reduced to slow growing lateral spurs bearing dense clusters of leaves at apex. Leaves solitary or in bundles of (1 or) 2-5(-8) when basally subtended by a leaf sheath ; leaf blade linear or needlelike, not decurrent. Cones unisexual . Pollen cones solitary or clustered, with numerous spirally arranged microsporophylls ; microsporophyll with 2 microsporangia; pollen usually 2-saccate (nonsaccate in Cedrus, Larix, Pseudotsuga, and most species of Tsuga) . Seed cones erect or pendulous, maturing in 1st, 2nd, or occasionally 3rd year, dehiscent or occasionally indehiscent, with many spirally arranged ovulate scales and bracts; ovulate scales usually smaller than bracts at pollination, with 2 upright ovules adaxially, free or only basally adnate with bracts, maturing into seed scales. Seed scales appressed, woody or leathery, variable in shape and size, with 2 seeds adaxially, persistent or deciduous after cone maturity. Bracts free or adnate basally with seed scales, well developed or rudimentary , exserted or included . Seeds terminally winged (except in some species of Pinus) . Cotyledons 2-18. Germination hypogeal or epigeal. 2n = 24* (almost always) .

Ten or eleven genera and ca. 235 species: N hemisphere; ten genera (two endemic) and 108 species (43 endemic, 24 introduced ) in China.

Species of the Pinaceae are among the most valuable and commercially important plants in the world. Most species are trees, and are often excellent sources of lumber, wood products, and resins; many are cultivated for afforestation and as ornamentals .Liguo Fu, Nan Li, Thomas S. Elias & Robert R. Mill "Pinaceae". in Flora of China Vol. 4 Page 11. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org.

Genus Tsuga

Trees evergreen ; crown conic; leading shoot usually drooping . Bark gray to brown, scaly , often deeply furrowed . Branches horizontal, often tending to be arranged in flattened "sprays" and arched downward; short (spur) shoots absent; young twigs and distal portions of stem flexuous and pendent, roughened by peglike projections persisting after leaves fall . Buds mostly rounded at apex, not resinous . Leaves borne singly, persisting several years, ± 2-ranked or radiating in all directions , flattened to somewhat angular; abruptly narrowed to a petiolelike base , set on peglike projections, these angled , projected forward, sheath absent; apex rounded or notched ; resin canals 1. Cones borne on year-old twigs. Pollen cones solitary, globose , brown. Seed cones maturing in 1 year, shedding seeds and falling soon thereafter or persisting for several years, pendent, ovoid , oblong , or oblong-cylindric, sessile or nearly so; scales persistent , shape various, thin, leathery, lacking apophysis and umbo ; bracts small, included . Seeds winged ; cotyledons 4--6. x =12.

Species ca. 10: Northern Hemisphere.

Species of Tsuga are found naturally in areas of relatively moist climates where water stresses are minimal. Most are conspicuous , if not dominant, members of the communities in which they occur.

Hemlock wood is moderately strong and pliable and lacks resin ducts. With the decline of associated species considered superior in commercial value, hemlocks have become important in the timber industry , especially for pulp. Hemlocks are also widely used for horticultural purposes; numerous cultivars have been developed.Ronald J. Taylor "Tsuga". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org.

Physical Description

Species Tsuga canadensis

Trees to 30m; trunk to 1.5m diam.; crown broadly conic. Bark brownish, scaly and fissured . Twigs yellow-brown, densely pubescent . Buds ovoid , 1.5--2.5mm. Leaves (5--) 15--20(--25) mm, mostly appearing 2-ranked, flattened; abaxial surface glaucous, with 2 broad, conspicuous stomatal bands , adaxial surface shiny green (yellow-green) ; margins minutely dentate , especially toward apex. Seed cones ovoid, 1.5--2.5 ´ 1--1.5cm; scales ovate to cuneate, 8--12 ´ 7--10mm, apex ± round, often projected outward. 2 n =24. [source]

ID Features: Pyramidal, medium-sized, needle evergreen tree with horizontal to. pendulous, graceful branches. Short flattened needles. Needles held in 2-ranked fashion. T. caroliniana, with which T. canadensis is often confused,. has more of its needles spirally distributed around its shoots. Shoots pubescent. Has minutely serrulate leaf margins, while T. caroliniana has. smooth margins. Twigs roughened by persistent leaf bases remaining after needles fall. Numerous, small cones.

Habit: A medium to large needle evergreen tree with a conical or pyramidal shape and soft, graceful, horizontal to pendulous branches.

Flowers: Monoecious, with male and female flowers. Small and not ornamentally important. • Bloom Period: n/a • Flower Conspicuous: None

Seeds: Fruit: Small cones, about 0.5" to 1.0" long. Turning light brown in the fall . Can be borne in large numbers.

Foliage: Flattened needle-like, dark green leaves grow in opposite rows • Foliage Shape: Linear • Normal foliage color: Green • Underside foliage: White • Juvenile foliage: Green • Mature foliage: Green • New foliage: Green • Spring foliage: Green • Summer foliage: Leaves are spirally arranged , but are held in a 2-ranked fashion. Needles are flattened. Needles are 0.25" to 0.75" long and about 0.10" wide. New foliage is dark green above with 2 whitish bands on the underside. Leaf margins minutely serrulate . Shoots pubescent . • Fall foliage: Evergreen , no fall color. • Winter foliage: Green

Size/Age/Growth

Growth Rate: Moderate. • Size: to 40 ft . tall, 25 ft. wide. Larger with age.

Landscaping

Landscape Uses: Lawn tree . Specimen. Can be sheared to form an effective screen or hedge . Excellent evergreen for screening use in shaded locations where most. needle evergreens fail. In groves or small groupings. Dwarf forms as rock garden plants , accent plants or foundation plants. • Liabilities: Not tolerant of pollution . Not tolerant of salt spray . Spider mites . Deer like to browse the foliage or rub off the bark with their antlers. Not tolerant of heat or drought . Hemlock wooly adelgid is a new and devastating insect pest that can be. easily controlled, but left unchecked can kill large plants in 3 years. • Care: Follow a regular watering schedule during the first growing season to establish a deep, extensive root system. Feed with a general purpose fertilizer before new growth begins in spring . For a tidy, neat appearance , shear annually to shape .

Habitat

Moist rocky ridges , ravines , and hillsides; 600--1800m. [source]

Typically found on northern and eastern slopes with cooler, moister environmental conditions . Zone 3.

Typically found at an altitude of 0 to 3,108 meters (0 to 10,197 feet).Mean = 337.590 meters (1,107.579 feet), Standard Deviation = 263.760 based on 624 observations. Altitude information for each observation from British Oceanographic Data Centre.

Biology

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Growth

Culture: Best growth on cool, moist, well-drained soils. Transplant from containers or B&B. Avoid dry soils and hot locations. Dislikes very windy sites. Full sun or partial shade is best. Tolerant of relatively heavy shade. Can be pruned heavily in the spring for hedging.

Soil: Minimum pH: 6.1 • Maximum pH: 7.8

Sunlight: Sun Exposure: Full to partial sun

Moisture: Water Requirements: Water regularly, when top 3" of soil is dry.

Temperature: Heat Zones: High: 8 (>90 to 120 days) Low:3 (>7 to 14 days) (map) • Cold Hardiness: 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b. (map)

Taxonomy

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Domain: Eukaryota () - Whittaker & Margulis,1978
- Kingdom: Plantae () - Haeckel, 1866 - Plants
  - Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
    - Phylum: Magnoliophyta () - Sinnott, 1935 Ex Cavalier-Smith, 1998 - Flowering Plants
      - Subphylum: Euphyllophytina ()
        Infraphylum: Radiatopses () - Kenrick & Crane, 1997
        Class: Pinopsida ()
        Order: Pinales ()
        Family: Pinaceae () - Lindley, 1836, Nom. Cons. - Pine Family
        Subfamily: Commelinoideae ()
        Tribe: Tradescantieae ()
        Genus: Tsuga () - (Endlicher) Carrière, 185. 1855 - Hemlock [Japanese tsuga, name for native hemlocks of Japan]
        Specific epithet: canadensis - Carrière
        Botanical name: - Tsuga canadensis Carrière

Ambiguous Synonyms

Abies americana Mill.
Picea canadensis (Michx.) Link
Pinus americana Du Roi
Pinus canadensis L.

Unambiguous Synonyms

Abies canadensis Michx.
Abies curvifolia Salisb.
Pinus pendula Salisb.
Tsuga americana (Mill.) Farwell
Tsuga canadensis (L.) Carr.
Tsuga canadensis (L.) Carriere
Tsuga canadensis L.

Notes

Name status: accepted name . Latest taxonomic scrutiny: Farjon A., 11-Jan-2006.

A tentatively accepted name in the RHS Horticultural Database.

Place of publication : Traité gén. conif. 189. 1855

Name verified on 15-May-1992 by ARS Systematic Botanists. Last updated: 01-Dec-1999

Similar Species

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Members of the genus Tsuga

There are approximately 140 species in this genus. Here are just 100 of them:

Bibliography

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Boutelje, J. B. 1980. Encyclopedia of world timbers, names and technical literature. (Ency WTimber)
Craker, L. E. & J. E. Simon, eds. 1986–1987. Herbs, spices, and medicinal plants, 2 vols. (HerbSpices)
Duke, J. A. et al. 2002. CRC Handbook of medicinal herbs. (CRC MedHerbs ed2)
FNA Editorial Committee. 1993–. Flora of North America. (F NAmer)
Farjon, A. 2001. World Checklist and Bibliograpy of Conifers. 2nd edition. The Royal Botanic Gardens, Kew.
Huxley, A., ed. 1992. The new Royal Horticultural Society dictionary of gardening. (Dict Gard) 4:526.
McGuffin, M. et al., eds. 2000. Herbs of commerce, ed. 2. (Herbs Commerce ed2)
Silba, J. 1986. Encyclopaedia Coniferae. Phytologia Mem. 8:213.
Cheng Wan-chün, Fu Li-kuo, Law Yu-wu, Fu Shu-hsia, Wang Wen-tsai, Chu Cheng-de, Chao Chi-son & Chen Chia-jui. 1978. Pinaceae. In: Cheng Wan-chün & Fu Li-kuo, eds., Fl. Reipubl. Popularis Sin. 7: 32-281.
Cheng Wan-chün, Fu Li-kuo, Law Yu-wu, Fu Shu-hsia, Wang Wen-tsai, Chu Cheng-de, Chao Chi-son & Chen Chia-jui. 1978. Pinaceae. In: Cheng Wan-chün & Fu Li-kuo, eds., Fl. Reipubl. Popularis Sin. 7: 32-281.

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Notes

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Contributors

"Tsuga canadensis". in Flora of North America Vol. 2. Published by Oxford University Press. Online at EFloras.org.
Brands, S.J. (comp.) 1989-2007. Systema Naturae 2000. The Taxonomicon. Universal Taxonomic Services, Amsterdam, The Netherlands. Accessed April 1, 2007.
Conifer Specialist Group 1998. In IUCN 2008. 2008 IUCN Red List of Threatened Species. IUCNRedList.org. Downloaded July 19, 2008.
Farjon, A. 11-Jan-2006 (from Conifer Database, Jun 2006).
Global Biodiversity Information Facility. Accessed November 19, 2007. http://www.gbif.org Mediated distribution data from 19 providers.
The International Plant Names Index. Accessed Jan 19, 2007.
USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL (April 24, 2008)
United States National Arboretum, Washington D.C.
Universal Biological Indexer and Organizer. uBio.org accessed July 17, 2008.

Data Sources

Accessed through GBIF Data Portal November 19, 2007:

Conservatoire botanique national du Bassin parisien, Conservatoire botanique national du Bassin parisien
Forest Research Institute, Department of Natural Forests, Herbarium
GBIF-Spain, Real Jardin Botanico
, Vascular Plant Herbarium
Herbario SANT, Universidade de Santiago de Compostela, SANT herbarium vascular plant collection
Missouri Botanical Garden, Missouri Botanical Garden
Steiermärkisches Landesmuseum Joanneum - Herbarium GJO, Herbarium GJO
The New York Botanical Garden, Bronx River Bioblitz
The Swedish Museum of Natural History
, Herbarium of Oskarshamn
UK National Biodiversity Network, Botanical Society of the British Isles - Vascular Plants Database
USDA PLANTS, USDA PLANTS Database
University of Alabama Biodiversity and Systematics, Herbarium

Identifiers

Biodiversity Heritage Library NamebankID: 2663775
Catalogue of Life Accepted Name Code: ITS-183397
Global Biodiversity Information Facility Taxonkey: 14705860
Globally Unique Identifier: urn:lsid:ipni.org:names:264005-1
GRIN Nomen Number: 40698

Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 183397
International Plant Names Index (IPNI) ID: 264005-1
IUCN ID: 42431
Natural Heritage Network Species Identifier: PGPIN06010
Zipcode Zoo Species Identifier: 193

Tsuga canadensis

Interesting Facts

Common Names

Description

Family Pinaceae

Genus Tsuga

Physical Description

Species Tsuga canadensis

Size/Age/Growth

Landscaping

Habitat

Biology

Growth

Taxonomy

Ambiguous Synonyms

Unambiguous Synonyms

Notes

Similar Species

Members of the genus Tsuga

Bibliography

More Info

Notes

Contributors

Data Sources

Identifiers

Footnotes