China cypress
| China cypress | ||||||||||||
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Chinese cypress branches ( Glyptostrobus pensilis ) with cones |
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| Scientific name | ||||||||||||
| Glyptostrobus pensilis | ||||||||||||
| ( Staunton ex D.Don ) K.Koch |
The Chinese cypress ( Glyptostrobus pensilis ), also called water spruce , is a species of conifers native to China, Vietnam and Laos . It is the only recent species of the genus of the water spruce ( Glyptostrobus ) from the family of the cypress family (Cupressaceae). It represents a living fossil .
description
Habitus
The china cypress is a tree that reaches heights of 8 to 25 m. The trunk is widened to a height of about 70 cm and heavily furrowed. In this area, trunk diameters of 60 to 120 cm are achieved. The bark is gray to gray-brown in color and comes off the tree in long, irregular strips. The treetop is conical. There are long and short shoots . The lower branches stick out more horizontally, the upper branches are more upright.
root
The glyptostrobus pensilis forms in youth a taproot that sets an age of around 10 years, the growth in length or bends to the side. It penetrates at depths of over 2 m. Old trees have strongly developed lateral roots. The root wood consists of a loose wood fabric with a high aerenchyma content. Each tree forms one or two respiratory roots that protrude up to 70 cm above the ground or water level.
Wood
The wood of the china cypress is soft, light and finely structured. The reddish brown heartwood differs in color from the yellowish brown sapwood . It is resistant to moisture. The density with a wood moisture content of 15 percent is between 0.37 and 0.42 g / cm³. With a bulk density of 0.12 g / cm³, the root wood is even lighter and also softer.
Foliage
The china cypress is a semi-evergreen tree and forms three different types of leaves , only one of which remains on the tree in winter. The first type are scale leaves, which are arranged helically on young or perennial long shoots. They have white stomata , are relatively thick and between 2 and 3 mm long. They stay on the tree for two to three years and are green even in winter. The second type are thin needle-shaped leaves, which are also screwy but parted on short shoots. They have a narrow base and are sharply pointed. A row of stomata runs along the central rib on the upper side of the leaf. They are between 1 and 3 cm long and between 1.5 and 4 mm wide. They fall off together with the short shoots towards winter. The third type are awl, slightly curved leaves that are either radially protruding or arranged in three rows on short shoots. The apex can be both blunt and pointed. They are between 4 and 11 mm long. They also fall off with the short shoots in winter.
Flowers, cones and seeds
The china cypress is monoecious ( monoecious ). Young trees only develop female cones. The flowering period extends from January to February. The elliptical, around 3 mm long and 4 mm wide male cones consist of 15 to 20 scale-like stamens . They are green at the beginning of their development and turn purple-bluish to dark blue when they bloom. The female cones are located at the ends of the short shoots. At flowering time, they are roughly horizontal, the pollination droplets stand freely in the air stream and are visible from the outside and are only about 2 mm long and 1 mm wide. The female cones consist of 20 to 22 green, egg-shaped cone scales, which are arranged in roof tiles. Each cone scale has 2 (to 3) ovules. The egg-shaped, initially green, when ripe in October light brown cones are 2 to 2.5 cm long and 1.3 to 1.5 cm wide. At maturity they stand upright. The woody cone scales that taper towards the base are rounded at the top. Cover and seed scales have grown together at the base.
The brown seeds are 5 to 7 mm long and 3 to 4 mm wide. They are elliptical in shape and appear slightly compressed. Each seed has a wing 4 to 7 mm wide. The thousand grain weight is around 12.5 g.
Per seedling are four to five cotyledons ( cotyledons ) are present.
Chromosome number
The number of chromosomes is 2n = 22.
Distribution and location
The china cypress is endemic to China . The center of its natural range extends over the delta of the Pearl River in Guangdong Province as well as over central parts of Fujian Province and the lower reaches of the Minjiang River . Much of the stock was artificially created; however, there are still natural populations. Further stocks are located in the eastern and western parts of Guangdong Province, eastern and northern Fujian, eastern Jiangxi and southeastern Guangxi and Yunnan . It was widely grown as an ornamental tree in the Lushan Mountains, as well as in Shanghai , Hangzhou, and Hong Kong . According to WCSP, outside of China, it originally occurs in Laos and Vietnam as well.
The first attempt at cultivation took place in the USA in 1812, and in Europe after 1830. The china cypress is threatened with extinction in its natural occurrence as a wildly growing species due to logging.
The china cypress is a tree species of the warm, humid climate. The rainfall in the natural range is around 1,600 mm / year. It prefers locations with high humidity and alluvial soils with high water supply. Due to its breathing roots, it is adapted to changing water levels. The pH should be between 7 and 8. A soil salinity of up to 0.28 percent is tolerated. It is a species of light tree.
Paleobotany
During the Cretaceous Period , species of the genus Glyptostrobus were among the most common representatives of the cypress family (Cupressaceae). The genus previously had a distribution in large parts of the northern hemisphere . It was most widespread in the Paleocene . They were important trees in the brown coal swamps. The genus with the only species today was pushed back to its present area before and during the Ice Ages. Fossil remains of the genus were important objects of investigation for studying the evolution of seed plants.
Diseases and pests
Stocks that were planted in Japan are attacked by the fungus Cercospora sequoiae , which causes severe loss of needles and shoots and can cause the plant to die. The disease was probably transmitted from the sickle fir ( Cryptomeria japonica ) to the Chinese cypress.
use
Because of the very intensive root system, the china cypress is often planted along dykes and dams in order to fortify them.
The wood is used as construction and furniture wood and because of its resistance to moisture also in bridge construction. Because of the buoyancy in the water, swim belts and lifebuoys are made from them.
Systematics
First description and synonyms
This species was described in 1828 under the taxon Thuja pensilis in the second edition of the work A description of the genus Pinus by the English botanist Aylmer Bourke Lambert , which was created with the assistance of David Don ; the description itself is ascribed to the Irish-British botanist George Leonard Staunton , who died in 1801 . Only five years later, another description by the French botanist Adolphe Brongniart was given in 1833 under the taxon Taxodium japonicum (Thunb. Ex L. f.) Brongn. var. heterophyllum Brongn. published in which the plant was considered a subspecies of the sickle fir .
The Austrian botanist Stephan Ladislaus Endlicher , who referred to the more recent description as Basionym , placed the plant again as a separate species in 1847 under the taxon Glyptostrobus heterophyllus (Brongn.) Endl. into a newly established own genus Glyptostrobus . The German botanist Karl Heinrich Koch held on to the new genus assignment in 1873, but referred to the older basionym Thuja pensilis with the taxon Glyptostrobus pensilis, which is valid today .
Other synonyms for this species are Glyptostrobus aquaticus (Roxb.) R. Parker , Glyptostrobus sinensis A. Henry ex Loder or Glyptostrobus lineatus auct. non (Poir.) Druce .
swell
- Schütt, Weisgerber, Schuck, Lang, Stimm, Roloff: Lexicon of Conifers . Nikol, Hamburg 2008, ISBN 3-933203-80-5 , p. 197-203 .
- Christopher J. Earle: Description and systematics of the species at The Gymnosperm Database, 2008. (English)
Individual evidence
- ↑ a b c Rafaël Govaerts (Ed.): Glyptostrobus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 1, 2019.
- ↑ a b c Armin Jagel, Veit Martin Dörken: The cones of the cypress family (Cupressaceae) - Part 1: Subfamilies Cunninghamioideae, Athrotaxoideae, Taiwanioideae, Sequoioideae, Taxodioideae. Communications from the German Dendrological Society, Vol. 100, 2015, pp. 161–176.
- ↑ AB Lambert: Descr. Pinus ed. 2, 2: 115. 1828. See entry at GRIN .
- ↑ Ann. Sci. Nat. (Paris) 30: 184. 1833. See entry at GRIN .
- ↑ Syn. Conif. 70. 1847. See entry at GRIN .
- ^ Dendrology 2 (2): 191. 1873. See entry at GRIN .
Web links
- Glyptostrobus pensilis in the endangered Red List species the IUCN 2006. Posted by: Farjon et al , 2005. Retrieved on 6 May, 2006.