Hemlocks
| Hemlocks | ||||||||||||
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Tsuga chinensis var. Formosana |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Tsuga | ||||||||||||
| ( Final ) Carrière |
The hemlock or hemlock ( Tsuga ) constitute a genus within the family of the Pinaceae (Pinaceae).
Origin of the common names
Hemlock is the translation from the English hemlock . This name comes from the smell of the grated needles of the West American hemlock , which is very similar to the smell of the ground elder , a relatively close relative of the hemlock.
description
Vegetative characteristics
The hemlocks are evergreen trees . The oldest are probably Tsuga mertensiana , of which it is said that there are 1,400-year-old specimens, 800-year-old specimens can be detected in British Columbia . The tallest tree in the genus is a specimen of Tsuga heterophylla with a stature height of 55 meters, a trunk diameter (dbh) of 259 centimeters and a crown diameter of 20 meters at Quisitis Point in the Pacific Rim National Park in British Columbia (report by Stoltmann 1987).
The bark is gray to brown, scaly and often deeply furrowed.
The treetop is conical to irregularly ovoid (in some Asian species). The tops of the trees and the otherwise horizontal branches often overhang.
The needles, arranged more or less in two lines or around the branch, last for a few years, are flat to slightly angular, with a base that is stem-like and a piercing to rounded end. The stomata are in two rows on the underside of the needle; only in Tsuga mertensiana are there stomata on the upper side. Each needle has a resin channel. The buds are not resinous. The seedling has (four to six cotyledons cotyledons ).
Generative characteristics
Tsuga species are single sexed ( monoecious ). The male cones, which are spherical and brown with a diameter of less than 8 millimeters, stand alone on annual twigs. The female cones are on annual branches; they take five to seven months to ripen and soon after the seeds are released they either fall off or remain on the tree for a few years. The cone falls off as a whole. The female cones, hanging from very short stems at most, are ovate to oblong, only oblong-cylindrical in Tsuga mertensiana . The cone scales are thin, leathery and variable in shape; they are mostly smooth and hairy only in Tsuga mertensiana . The deck scales are small.
The seeds are 3 to 5 millimeters long and 2 to 3 millimeters in diameter. You have many small resin containers. Their thin wings are 5 to 10 millimeters long.
In all Tsuga species, the basic chromosome number is x = 12 with a chromosome number of 2n = 24.
Occurrence
The areas Tsuga TYPES lie in the temperate regions of North America and East Asia . Tsuga natural sites are always in relatively humid climates with little drought stress . In their habitats they are mostly the dominant plant species.
The genus Tsuga was also native to Europe in the Tertiary , but died out during the Ice Ages .
Systematics
It was first published in 1847 as the Pinus sect section . Tsuga Endl. by Stephan Ladislaus Endlicher Synopsis Coniferarum , page 83 with the type species Abies tsuga Siebold & Zucc. . It gained the status of a genus Tsuga (Endl.) Carrière in 1855 by Élie Abel Carrière in Traité Général des Conifères ou description de toutes les espèces et variétés aujourd'hui connues, avec leur synonymie, l'indication des procédés de culture et de multiplication qu 'il convient de leur appliquer , page 185 received. The type species is Tsuga Sieboldii Carrière . The scientific name Tsuga is the Japanese name ( Japanese 栂 ) of the southern Japanese hemlock .
The genus of hemlocks ( Tsuga ) is divided into two sub-genera with a total of about ten species:
- Subgenus Tsuga : There are nine species:
- Canadian hemlock ( Tsuga canadensis (L.) Carrière ): It is found in North America in eastern Canada in New Brunswick , Nova Scotia , southeastern Ontario , Prince Edward Island and southern Québec and in the eastern to central US states southern Indiana , Maine , Massachusetts , Michigan , New Hampshire , New Jersey , New York , Ohio , Pennsylvania , Rhode Island , Vermont , West Virginia , Connecticut , eastern Minnesota , Wisconsin , northern Alabama , Delaware , northern Georgia , Kentucky , Maryland , North Carolina , South Carolina , Virginia as well as Tennessee . It thrives in moist locations at altitudes of 600 to 1800 meters.
- Carolina hemlock ( Tsuga caroliniana Engelmann ) It occurs in the southeastern US state of northeast Georgia, western North Carolina, South Carolina, southwest Virginia and Tennessee.
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Chinese hemlock ( Tsuga chinensis (Franchet) Pritzel ): There are around four varieties, depending on the author:
- Tsuga chinensis (Franchet) Pritzel var. Chinensis
- Tsuga chinensis var. Oblongisquamata W.C.Cheng & LKFu (Syn .: Tsuga oblongisquamata (WCCheng et LKFu) LKFu & Nan Li ): It occurs only in Zhouqu Xian in Gansu, in western Hubei and Sichuan .
- Tsuga chinensis var. Robusta W.C.Cheng & LKFu : It occurs only in Hubei and in the Yalong Valley in Sichuan.
- Tsuga chinensis var. Tchekiangensis (flous) WCCheng & LKFu (Syn .: Tsuga tchekiangensis flous ): It thrives in tropical karst at altitudes from 600 to 2,100 meters in northern Vietnam and the Chinese provinces of southeastern Yunnan , Guizhou , Hunan , Jiangxi , Zhejiang as well as northern Guangxi .
- Northern Japanese hemlock , or hemlock with different needles, ( Tsuga diversifolia (Maxim.) Masters , Syn .: Tsuga blaringhemii Flous ): It grows at altitudes of 700 to 2000 meters only on the Japanese islands of Honshu and Kyushu .
- Himalayan hemlock ( Tsuga dumosa (D.Don) Eichler , Syn .: Tsuga brunoniana (Wall.) Carrière , Tsuga yunnanensis (Franch.) E. Pritz. , Tsuga calcarea Downie , Tsuga dura Downie , Tsuga wardii Downie , Tsuga intermedia Hand .-Mazz. , Tsuga leptophylla Hand.-Mazz. , Tsuga chinensis subsp. Wardii (Downie) E. Murray , Tsuga dumosa subsp. Leptophylla (Hand.-Mazz.) E. Murray , Tsuga dumosa var. Yunnanensis (Franch.) Silba ): It occurs in the northern Indian states of Uttar Pradesh and Arunachal Pradesh , in Bhutan , Nepal , Sikkim , in northern Myanmar , in Vietnam, in southern Tibet and in the Chinese provinces of Sichuan, northern and western Yunnan.
- Tsuga forrestii Downie (Syn .: Tsuga chinensis subsp. Forrestii (Downie) AEMurray , Tsuga chinensis var. Forrestii (Downie) Silba ): It grows in the mountains and valleys at altitudes of 2000 to 3000 meters in the Chinese provinces of northeastern Guizhou (only Jiangkou: Fanjing Shan ), southwestern Sichuan and northwestern Yunnan.
- West American hemlock ( Tsuga heterophylla (Raf.) Sargent ): It thrives in forests on the coast up to medium montane altitudes at altitudes of 0 to 1500 meters in western North America from Alaska via the Canadian Alberta and British Columbia to the US state Washington , Idaho , Montana , Oregon and California .
- South Japanese hemlock ( Tsuga Sieboldii Carrière ): It occurs in the Japanese islands of central to western Honshu , Kyushu and Shikoku and in South Korea only in Kyongsang Puk (Ulleung-do).
- Tsuga ulleungensis G.P. Holman, Del Tredici, Havill, NSLee & CSCampb. : It wasfirst describedfrom Korea in 2017. It has so far only been found on the island of Ulleungdo on northern slopes at altitudes of 310 to 500 meters.
- Subgenus Hesperopeuce ( Engelmann) AEMurray : There is only one species:
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Mountain hemlock ( Tsuga mertensiana (Bongard) Carriere , Tsuga pattoniana (Balfour) Sénéclause ): It comes in western North America from southern Alaska through the Canadian British Columbia to the US states, northern Idaho, northwestern Montana , Oregon, Washington, Nevada , and northern to central California. There are two subspecies:
- Tsuga mertensiana subsp. grandicona Farjon
- Tsuga mertensiana (Bongard) Carrière subsp. mertensiana
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Mountain hemlock ( Tsuga mertensiana (Bongard) Carriere , Tsuga pattoniana (Balfour) Sénéclause ): It comes in western North America from southern Alaska through the Canadian British Columbia to the US states, northern Idaho, northwestern Montana , Oregon, Washington, Nevada , and northern to central California. There are two subspecies:
use
Few species are cultivated for forestry in Europe. Some species are used as ornamental plants in parks and gardens , sometimes as cultivated forms .
Due to its insensitivity to moisture, hemlock wood is used as an arrow shaft material in traditional archery . The resistance to moisture in combination with the lack of resin in the wood makes hemlock a high-quality material for sauna construction.
photos
Ripe cones of the Canadian hemlock ( Tsuga canadensis ).
Carolina hemlock branch ( Tsuga caroliniana ).
Branch with needles and cones of the southern Japanese hemlock ( Tsuga Sieboldii )
Branch with needles of the northern Japanese hemlock ( Tsuga diversifolia ).
Branch with needles of the mountain hemlock ( Tsuga mertensiana ).
swell
- Christopher J. Earle, 2019: Information on the genus at The Gymnosperm Database . (Sections Description and Systematics)
- Ronald J. Taylor: Tsuga (Endlicher) Carrière - the same text online as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico. Volume 2: Pteridophytes and Gymnosperms. Oxford University Press, New York and Oxford, 1993, ISBN 0-19-508242-7 .
- Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinaceae. : Tsuga (Endlicher) Carrière , p. 39 - online with the same text as the printed work , In: Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China. Volume 4: Cycadaceae through Fagaceae. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 1999, ISBN 0-915279-70-3 .
- Nathan P. Havill, Christopher S. Campbell, Thomas F. Vining, Ben LePage, Randall J. Bayer, Michael J. Donoghue: Phylogeny and biogeography of Tsuga (Pinaceae) inferred from nuclear ribosomal ITS and chloroplast DNA sequence data. In: Systematic Botany , Volume 33, Issue 3, 2008, pp. 478-789. doi : 10.1600 / 036364408785679770 Full text PDF.
Individual evidence
- ↑ a b c d e Ronald J. Taylor: Tsuga (Endlicher) Carrière - the same text online as the printed work , In: Flora of North America Editorial Committee (ed.): Flora of North America North of Mexico. Volume 2: Pteridophytes and Gymnosperms. Oxford University Press, New York and Oxford, 1993, ISBN 0-19-508242-7 .
- ^ Tsuga at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ^ Tsuga at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved April 11, 2019.
- ↑ Peter Loewer: Jefferson's Garden . Stackpole Books, 2004, ISBN 0-8117-0076-3 , pp. 233 ( limited preview in Google Book search).
- ↑ a b c d e f g h i j k Christopher J. Earle: Information on the genus at The Gymnosperm Database , 2019.
- ^ A b Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinaceae. : Tsuga (Endlicher) Carrière , p. 39 - online with the same text as the printed work , In: Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China. Volume 4: Cycadaceae through Fagaceae. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 1999, ISBN 0-915279-70-3 .
- ↑ Tsuga in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved April 11, 2019.
- ↑ Garth Holman, Peter Del Tredici, Nathan Havill, Nam Sook Lee, Richard Cronn, Kevin Cushman, Sarah Mathews, Linda Raubeson, Christopher S. Campbell: A New Species and Introgression in Eastern Asian Hemlocks (Pinaceae: Tsuga). In: Systematic Botany , Volume 42, Issue 4, 2017, pp. 1–15. DOI: 10.1600 / 036364417X696474
- ↑ sauna-portal.com/sauna-selbstbau/sauna-holz . Retrieved December 19, 2012.
Web links
further reading
- BA LePage: A new species of Tsuga (Pinaceae) from the middle Eocene of Axel Heiberg Island, Canada, and an assessment of the evolution and biogeographical history of the genus. In: Botanical Journal of the Linnean Society , Volume 141, 2003, pp. 257-296.
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