Pinus wangii
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Pinus wangii in the Kunming Botanical Gardens |
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| Hu & WCCheng |
Pinus wangii is a medium-sized, evergreen conifer from the genus of pine ( Pinus ) with needles that grow in groups of five and are 2.5 to 6 centimeters long. The seed cones usually reach a length of 4 to 10, rarely 15 centimeters. The natural range is in southern China and probably in Vietnam. Pinus wangii is classified as critically endangered onthe IUCN Red List . Trees are known from only four locations, three of which are close to each other. The population continues to decline due to the continued felling of trees.
description
Appearance
Pinus wangii grows as an evergreen tree up to 20 meters high. The trunk reaches a breast height diameter of up to 60 centimeters. The trunk bark of young trees and the bark of the branches are smooth and thin. The trunk bark of older trees is brown, dark brown or gray-brown, scaly and flakes off. The branches are widely spreading and form a broad, umbrella-shaped or irregular, flat crown. The needled branches are thin. Young shoots are initially dark red-brown and densely hairy, in the second or third year they are gray-brown and hairless or with residual hair in the grooves of the bark.
Buds and needles
The vegetative buds are brown, ovoid to cylindrical and not resinous. The lower leaves are brown. The needles grow in groups of five in an early sloping needle sheath made of delicate, brown scales. The needles are protruding or slightly bent towards the shoot, flexible, 2.5 to 6 centimeters long and 1 to 1.5 millimeters wide. The edge of the needle is very finely sawn. The color of the needles is green, the two adaxial sides have stomata lines . Three resin channels are formed.
Cones and seeds
The pollen cones grow in small groups. They are short-cylindrical.
The seed cones grow individually or in twos or threes at the base of twigs on sturdy stems 1.5 to 2 centimeters long. They are variable in size and shape and can be small ovoid to long cylindrical, are initially upright and are later sloping down to hanging. They are usually 4 to 10 and sometimes up to 15 centimeters long with a diameter of 2 to 4.5 centimeters. Ripe cones are yellowish brown or dark brown and gray-brown when exposed to the weather. The seed scales are soft woody, more or less flexible at the base, wedge-shaped to elongated, 2 to 3 centimeters long and 1.5 to 2 centimeters wide. The apophysis is rhombic and elongated, curved, or more or less straight at the base and tip of the cone. The tip is thin and straight or slightly curved, less often curved. The umbo lies terminally and is small, lowered or blunt.
The seeds are pale brown, obovate or ellipsoid, 8 to 10 millimeters long and about 6 millimeters wide. The seed wing is well developed, about 16 millimeters long and 7 millimeters wide.
Distribution, ecology and endangerment
The natural range of Pinus wangii is in the southeast of the Chinese province of Yunnan in the counties of Malipo and Xichou and probably in Vietnam in Mai Chau . The species may be restricted to the limestone -dominated areas of southern China and northern Vietnam, where it occurs on steep slopes and scattered on mountain ridges. They are found together with Quercus variabilis and other mostly small-leaved, evergreen trees and shrubs. The Chinese hemlock ( Tsuga chinensis ), Taxus chinensis and Amentotaxus yunnanensis also grow . Pinus wangii grows at altitudes of mostly 500 to 1800 meters. The distribution area is assigned to winter hardiness zone 8 with mean annual minimum temperatures of −12.1 to −6.7 ° Celsius (10 to 20 ° Fahrenheit ).
In the Red List of the IUCN is Pinus Wangii as endangered ( "Endangered") classified. The distribution area is very small and the species is only documented by nine herbarium finds of four growing species. The specimen copies are held in China, Great Britain, and the United States. Three of these growing sites are close together, one a little to the east. The extent of occurrence extends over 1633 square kilometers, but the species inhabits less than 80 square kilometers (area of occupancy), which are also not in protected areas. Felling of the trees has caused the stocks in accessible areas to disappear and, despite a ban on cutting down the trees, the stocks continue to decline.
Systematics and research history
Pinus wangii is a species from the genus of the pines ( Pinus ), in which it is assigned to the subgenus Strobus , Section Quinquefoliae , Subsection Strobus . The species was only in 1948 from hu xiansu and Zheng Wanjun in the Bulletin of the Fan Memorial Institute of Biology firstdescribed . The generic name Pinus was already used by the Romans for several types of pine. The specific epithet wangii honors the botanist CW Wang, who found the type specimen in Yunnan.
The Flora of China also recognizes Pinus wangii as a separate species. Several closely related species of pine exist in southwest China and Vietnam, including Pinus fenzeliana and Pinus dalatensis . Hu Xiansu and Zheng Wanjun saw similarities with Pinus parviflora from Japan, but the two species are no longer considered to be very close. Nevertheless, James E. Eckenwalder assigns representatives as the variety Pinus parviflora var. Wangii to the species Pinus parviflora . However, no other synonyms of the species are known. According to the Flora of China , the occurrences in Vietnam should possibly be assigned to the species Pinus dalatensis Ferré .
No longer Pinus Wangii Hu & WCCheng expected: Pinus Wangii subsp. kwangtungensis (Chun ex Tsiang) Businský ; it is used as a synonym for Pinus fenzeliana Hand.-Mazz. posed.
Pinus wangii is similar to Pinus fenzeliana , but differs in the length of the needles, the somewhat smaller cones and the color and hairiness of the annual shoots.
use
The wood from Pinus wangii is used locally as construction timber , to build bridges and to make furniture. The species is rarely used in horticulture. Few, mostly young, trees are found in botanical gardens in China, Great Britain, and the United States.
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 609, 781-782 .
- James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 461 .
- 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. 24 (English).
- Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Nikol, Hamburg 2005, ISBN 3-937872-16-7 , p. 487 (reprint from 1996).
Individual evidence
- ↑ a b c d e f g Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 781
- ↑ a b c d e f g Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus wangii , in Flora of China , Volume 4, p. 24
- ↑ a b Pinus wangii in the endangered Red List species the IUCN 2013. Posted by: Aljos Farjon, 2012. Accessed August 11, 2013.
- ^ A b Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 782
- ↑ a b Christopher J. Earle: Pinus wangii. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed on August 11, 2013 .
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 609
- ↑ Pinus wangii. In: The International Plant Name Index. Retrieved August 11, 2013 .
- ↑ Exactly: Etymological Dictionary of Botanical Plant Names , p. 487
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 781-782
- ↑ James E. Eckenwalder: Conifers of the World , p. 461
- ↑ Pinus wangii. In: The Plant List. Retrieved August 11, 2013 .
- ↑ Rafaël Govaerts (ed.): Pinus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 26, 2019.
Web links
- Pinus wangii at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed August 11, 2013.