Nut slices
| Nut slices | ||||||||||||
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Florida nut slice ( Torreya taxifolia ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Torreya | ||||||||||||
| Arn. |
The nut slices ( Torreya ) form a genus of plants in the yew family (Taxaceae). Today it has a disjoint area with species in the southeastern and western USA and in China and Japan.
description
Vegetative characteristics
Nut slice species are evergreen shrubs or small trees . The branches are arranged in whorls and the twigs are almost opposite to almost whorled. The bark is brown to grayish-brown. The needles appear to be arranged in two rows on the branch. The winter buds have some cross-opposed pairs of bud scales. The seedling has two cotyledons ( cotyledons ).
The leaves are cross-opposite or almost opposite and arranged in two lines on the branches. The leaves , twisted at their base, are leathery and linear or linear-lanceolate with a sloping base and a sharply pointed upper end. On the slightly convex underside of the leaf there are two stomatal ligaments and resin canals and the median nerve is more or less indistinctly discernible.
Generative characteristics
They are usually dioecious, separate sexes ( diocesan ), very rarely monoecious ( monoecious ).
The male cones are single and lateral on a short shaft. The male cones are ellipsoidal or short columnar and contain six to eight whorls with four microsporophylls each . Each microsporophyll rarely has three or mostly four hanging pollen sacs (microsporangia).
The female cones are sitting in pairs in the leaf axils. The female cones have two pairs of cross-opposed cone scales and a lateral one. There is only one erect ovule . There is a succulent aril at the base of the durable cone scales. This green seed coat ( arillus ) surrounds the seed ; both structures together look like stone fruit. The seeds need about two years from fertilization to maturity in autumn.
The basic chromosome number is x = 11; there are chromosome numbers of 2n = 22.
Systematics and distribution
The genus Torreya was established in 1838 by George Arnott Walker Arnott in Annals of Natural History , 1, pp. 130-132. There are other publications for this generic name, but that of Arnott has been established as the valid one. The botanical genus name Torreya honors the American doctor, chemist and botanist John Torrey (1796–1873). A synonym for Torreya Arn. is Tumion Raf.
The genus Torreya today has a disjoint area with species that occur only in North America (in the southeastern and western USA) or only in Asia (in China and Japan). The Torreya species occur today predominantly on the Pacific coasts and their distribution indicates a formerly continuous distribution zone over the Bering Strait .
There are six species in the genus Torreya , which are given here with their range:
- Californian nut slice ( Torreya californica Torr. ): It only thrives in the coastal mountains and in the Sierra Nevada at altitudes from 0 to 2000 meters in California .
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Torreya fargesii Franchet : There are two varieties:
- Torreya fargesii Franchet var. Fargesii (Syn .: Torreya grandis var. Fargesii (Franchet) Silba ): It thrives sporadically in coniferous and laurel forests at altitudes of 1000 to 1800 meters in the Chinese provinces of western Hubei , northwestern Hunan , Jiangxi , southern Shaanxi , Sichuan and maybe in southern Anhui.
- Torreya fargesii var. Yunnanensis (WCCheng & LKFu) N.Kang (Syn .: Torreya yunnanensis W.C.Cheng & LKFu , Torreya grandis var. Yunnanensis (WCCheng & LKFu) Silba ): This endemic thrives in coniferous and mixed forests in warm temperate areas As a locally common forest tree at altitudes of 1500 to 3400 meters only in northwestern Yunnan (in Gongshan Drungzu Nuzu Zizhixian, Lijiang Naxizu Zizhixian, Weixi Xian, Zhongdian Xian)
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Large nut slice ( Torreya grandis Fort. Ex Lindl. ): There are two varieties:
- Torreya grandis Fort. Ex Lindl. var. grandis (Syn .: Torreya parvifolia T.P.Yi, Lin Yang & TLLong , Torreya fargesii subsp. parvifolia Silba , Torreya grandis var. chingii Hu , Torreya grandis var. dielsii Hu , Torreya grandis var. merrillii Hu , Torreya grandis var. sargentii Hu ): It thrives on mountains and open valleys at altitudes between 200 and 1400 meters in the Chinese provinces of southern Anhui , northern Fujian , northeastern Guizhou (only in Songtao), western Hunan, southern Jiangsu , northern Jiangxi and Zhejiang .
- Torreya grandis var. Jiulongshanensis Z.Y.Li et al .: It was first described in 1995. This endemic thrives in the mountains at altitudes of around 800 meters only in Suichang Xian in southern Zhejiang.
- Torreya jackii Chun : It thrives in forests at altitudes of 400 to 1000 meters in the Chinese provinces of northern Fujian , northeastern Jiangxi and southern Zhejiang .
- Japanese nut slice ( Torreya nucifera Sieb. & Zucc. ), Also called Japanese stinky chew: it is originally only found in Japan and Korea. It is also used as an ornamental plant.
- Yew-leaved nut slice ( Torreya taxifolia Arn. ): This endemic thrives at altitudes of 15 to 30 meters only along the Apalachicola River in Georgia (only in Decatur County) and in Florida (only in Gadsden, Jackson and Liberty Counties ).
swell
literature
- Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China . Volume 4: Cycadaceae through Fagaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 1999, ISBN 0-915279-70-3 , pp. 94 (English).
- Liguo Fu, Nan Li, Robert R. Mill: Taxaceae. : Torreya Arnott. , P. 94 - 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 .
- Matthew H. Hils: Taxaceae. : Torreya Arnott. - 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 .
- Jianhua Li, Charles C. Davis, Michael J. Donoghue, Susan Kelley, Peter Del Tredici: Phylogenetic relationships of Torreya (Taxaceae) inferred from sequences of nuclear ribosomal DNA its region . In: Harvard Papers in Botany . Volume 6 , 2001, pp. 275–281 (English, phylodiversity.net [PDF; 3.3 MB ; accessed on December 21, 2018]).
Individual evidence
- ^ A b Torreya in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
- ↑ a b c Matthew H. Hils: Taxaceae. : Torreya Arnott. - 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 .
- ^ W. Jardine, PJ Selby, WJ Hooker, Richard Taylor: Torreya, Arn. In: Annals of Natural History; or Magazine of Zoology, Botany, and Geology . Volume 1 . R. and JE Taylor , London 1938, pp. 130 f . (English, scanned from biodiversitylibrary.org [accessed December 21, 2018]).
- ↑ Torreya at Tropicos.org. Missouri Botanical Garden, St. Louis
- ↑ Lotte Burkhardt: Directory of eponymous plant names. Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin Berlin 2018. online.
- ↑ a b Christopher J. Earle: Torreya. In: The Gymnosperm Database. February 28, 2019, accessed May 3, 2019 .
- ↑ a b c d Walter Erhardt , Erich Götz, Nils Bödeker, Siegmund Seybold: The great pikeperch . Species and varieties. In: Encyclopedia of Plant Names . tape 2 . Verlag Eugen Ulmer, Stuttgart 2008, ISBN 978-3-8001-5406-7 .
- ↑ a b c d e f g Liguo Fu, Nan Li, Robert R. Mill: Taxaceae. : Torreya Arnott , p. 94 - 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 .
