Calocedrus rupestris
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| Aver. , THNguyên & PKLôc |
Calocedrus rupestris is a species of incense cedar ( Calocedrus ). The first description of this only in northern Vietnam took place occurring only kind of 2004.
description
Calocedrus rupestris grows as an evergreen tree that can reach heights of growth of up to 25 meters and trunk diameters ( breast height diameter ) of up to 100 centimeters. Branches that extend almost straight from the trunk form a broad, round crown . The gray-brown to brown, 8 to 12 millimeter thick bark is furrowed and peeled off in elongated strips. The wood has a light yellow color. The cross-opposed leaves , arranged in whorls in groups of four, are dimorphic along the branches , so there are two different leaf shapes. The vertical pair of leaves is flattened and the lateral pair of leaves is boat-shaped. The 1 to 7 millimeters long and 0.3 to 2.5 millimeters wide, scale-shaped leaves have a base that descends on the branch and a blunt upper end. The leaves are uniformly green in color and sometimes have several stomatal ligaments on the underside of the leaves that are difficult to recognize .
The flowering period extends from December to January. The male cones are initially light green and later turn light brown. The male cones are cylindrical with a length of 4.5 to 6 millimeters and a diameter of 1.5 to 2.2 millimeters. Each male cone contains microsporophylls with two to six pollen sacs . The microsporophylls have a length of 0.8 to 1.2 millimeters and a width of 1 to 1.2 millimeters, rounded, blunt or broad.
The greenish-brown female cones stand individually or in pairs at the branch ends. The female cones are egg-shaped with a length of 4 to 7 centimeters and a diameter of 2.5 to 4 millimeters. The cones probably ripen from September to October. The female cones contain four, rarely six cone scales, with two bearing no seeds. The two fertile cone scales each bear one or two seeds. The 4 to 5 millimeters large, egg-shaped seeds have two irregularly shaped wings.
Occurrence
The natural range of Calocedrus rupestris includes the northern part of Vietnam . You can find them in the provinces of Bắc Kạn , Cao Bằng , Hà Giang , Hòa Bình , Nghệ An , Quảng Bình and Sơn La . Since some stocks have been found near the borders with China and Laos , they are likely to exist in these countries as well.
Calocedrus rupestris thrives in the tropical monsoon climate with rainy summer months. The annual precipitation is depending on the location from 1200 to 3000 millimeters. In winter, frosts can occur in some locations. Calocedrus rupestris only grows in the tropical karst area .
Calocedrus rupestris thrives in mixed forests and evergreen coniferous forests as well as in pure stands. In pure stands there is a dense layer of bushes and herbs with a high level of species diversity.
Hazard and protection
Calocedrus rupestris is in the red list of the IUCN out as "Endangered" = "high risk". The total population is estimated to be less than 2500 fully grown specimens. The main risk factors are the use of wood and progressive deforestation together with a low rate of reproduction. Their habitat is considered to be very susceptible to climate changes such as less moisture and precipitation.
Taxonomy
Calocedrus rupestris is a kind from the genus of calocedrus ( Calocedrus ). It differs from the species Calocedrus macrolepis, which is also native to Vietnam, in that it has significantly smaller leaves and cones, whereby the seed cones usually only have four instead of six cone scales. The two species grow in different habitats and their ranges hardly overlap.
It was first described as Calocedrus rupestris in 2004 by Leonid Vladimirovich Averyanov , Tiên Hiêp Nguyên and Phan Kê Lôc in Issues of Basic Research in Life Sciences with direction in upland agriculture and forestry. Proceedings, the 2004th [sic] National Conference on Life Sciences Thai Nguyen University, September 23 . The specific epithet rupestris means rock-dwelling, so very appropriate for the rocky locations in the tropical karst.
use
The wood of Calocedrus rupestris is valued for its strength and fragrance and is very expensive. It is used for carpentry, interior finishing and making furniture. The wood is not only used in Vietnam, but also traded to China.
swell
- Christopher J. Earle: Calocedrus rupestris. In: The Gymnosperm Database. www.conifers.org, December 13, 2010, accessed November 18, 2011 .
- Aljos Farjon: A Handbook of the World's Conifers . tape 1 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 491-492 .
Individual evidence
- ↑ a b c d e f g h Christopher J. Earle: Calocedrus rupestris. In: The Gymnosperm Database. www.conifers.org, December 13, 2010, accessed November 18, 2011 .
- ↑ Calocedrus rupestris in the endangered Red List species the IUCN 2011. Posted by: Averyanov, L. & Thomas, P., 2008. Accessed November 18, 2011th
- ^ Farjon: A Handbook of the World's Conifers , p. 250
- ↑ Calocedrus rupestris at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed November 18, 2011.
- ^ Farjon: A Handbook of the World's Conifers , p. 251