Pinus yunnanensis

from Wikipedia, the free encyclopedia
Pinus yunnanensis
Pinus yunnanensis Stone Forest Kunming 1.jpg

Pinus yunnanensis

Systematics
Class : Coniferopsida
Order : Conifers (Coniferales)
Family : Pine family (Pinaceae)
Subfamily : Pinoideae
Genre : Pine ( Pinus )
Type : Pinus yunnanensis
Scientific name
Pinus yunnanensis
Franchet

Pinus yunnanensis is an evergreen conifer from the genus of the pine ( Pinus ) with 7 to 30 cm long needles and 5 to 11 cm long seed cones. The distribution area is in southwest China and extends from 400 to 3100 meters altitude. Adistinction is made betweentwo to three varieties . The species is of great economic importance in China, the wood is used in various ways, turpentine is obtainedfrom the resinand tannins from the bark.

description

Habitus

Pinus yunnanensis grows as an evergreen tree up to 30 meters high or, more rarely, as a shrub. The trunk of trees is monopodial and sometimes forked in the crown region. The trunk diameter can be up to 100 centimeters. The trunk bark is gray-brown, gray when exposed to the weather, longitudinally cracked, scaly, breaks into irregular plates and flakes off in small or large strips. The branches are horizontal or curve downwards and form a dome-shaped or flat crown. Needled branches are strong, rough and bare after Pulvini sheds the needles . Young shoots are thick, usually strong, reddish brown and later gray-brown. They can reach a length of 35 centimeters within a year.

Buds and needles

Twigs and needles

The winter buds are red-brown, ovate-elongated and pointed. Terminal buds reach a length of 25 millimeters, lateral buds are smaller and resin-free. The bud scales are pressed and red-brown. The needles rarely grow in pairs, usually in threes, in a permanent, 10 to 15 millimeter long, basal needle sheath. The needles are light green, straight, thin, flexible, slightly twisted, usually 7 to 20, rarely up to 30 centimeters long and 1 to 1.2 millimeters thick, with a fan-shaped, triangular or semicircular cross-section, with finely sawn edges and a pointed or pointed end . Only the longest needles are pendulous. Four or five resin channels in the center or closer to the surface are formed per needle . There are fine stomata lines on all needle sides .

Cones and seeds

Seed cones

The pollen cones are short cylindrical, about 2 inches long and yellow. The seed cones grow in pairs or in whorls of up to five cones. They are short stalked or almost sessile, 5 to 10 sometimes 11 centimeters long, almost symmetrical, closed ovoid-conical with diameters of 3.5 to 4.5 centimeters and open with a diameter of 5 to 7 centimeters. They open early, but then stay on the tree for several years. The seed scales are woody, stiff, oblong to obovate and, with the exception of the base, protrude horizontally. The apophysis is raised, differently shaped, keeled transversely and ripens from green to light to chestnut brown. The umbo is flat or raised and reinforced with a small spike. The seeds are egg-shaped, 4 to 5 millimeters long and brown. The seed wing is 12 to 15 millimeters long, about 6 millimeters wide, light brown or gray-brown. Pollination takes place in April and May, the seeds ripen in October.

The number of chromosomes is 2n = 24.

Distribution, ecology and endangerment

The natural range of Pinus yunnanensis is in southwest China in the south of the Sichuan province , in Yunnan , in the east of Guizhou and in the east of Guangxi . Pinus yunnanensis forms extensive forests in valleys, gorges and on mountain slopes in mountains at altitudes of 400 to 3100 meters. It often grows on dry and sunny slopes and sometimes reaches the tree line, where it forms alpine bushland. It thrives well on less fertile, flat and rocky soils and can withstand severe frost at high altitudes. It usually grows in pure stands, sometimes together with other pines ( Pinus ) such as Pinus armandii , Pinus tabuliformis and Pinus kesiya , but also with Keteleeria evelyniana and with covered trees and bushes.

In the Red List of the IUCN is Pinus yunnanensis be deemed not at risk ( "Lower Risk / least concern"). However, it should be noted that a reassessment is pending.

Systematics and research history

Pinus yunnanensis is a species from the genus of pines ( Pinus ) in which it is assigned to the subgenus Pinus , section Pinus and subsection Pinus . It was first scientifically described in 1899 by Adrien René Franchet . The generic name Pinus was already used by the Romans for several types of pine. The specific epithet yunnanensis refers to the Chinese province of Yunnan, from where it was first described scientifically.

Pinus yunnanensis is similar to Pinus tabuliformis and possibly forms the hybrid Pinus × densata with this species , which is called Pinus densata mast. species status is also granted. Pinus yunnanensis is sometimes viewed as a subspecies of Pinus kesiya or a variety of Pinus insularis , which itself is only considered a variety of Pinus kesiya var. Langbianensis . To clarify these points, more detailed genetic examinations are pending, until then the species status is mostly retained (status 2010).

There are two or three varieties :

  • Pinus yunnanensis var. Yunnanensis forms trees up to 30 meters high with not or only slightly hanging needles, 10 to 20 sometimes up to 30 centimeters long, with four to six resin canals. The seed cones open when ripe and fall off after the seeds have been released. The distribution area is in the south of Sichuan, in Yunnan and in the east of Guizhou and Guangxi.
  • Pinus yunnanensis var. Pygmaea (Hsueh f.) Hsueh f. grows bush-shaped up to 2 meters high in alpine surroundings. The needles are 7 to 13 inches long, stiff, non-pendulous, and have two or three resin channels. The seed cones grow in groups and stay on the tree for a long time, the seeds are not released in a certain period of the year, but depending on the environmental conditions. The distribution area is in the southwest of Sichuan and in Yunnan. There it grows at altitudes between 2200 and 3100 meters.
  • Pinus yunnanensis var. Tenuifolia W.C.Cheng & YWLaw forms up to 30 meters tall trees with hanging, length 20 to 30 centimeters and less than 1 millimeter thick needles with four to six resin channels. The seed cones open when ripe and fall off after the seeds have been released. The distribution area is in Guangxi and Guizhou in river valleys at heights of 400 to 1200 meters. However, the differences between this variety and yunnanensis are so small that Aljos Farjon does not recognize the variety tenuifolia and assigns it to the variety yunnanensis .

use

Seeds

Pinus yunnanensis is of great economic importance in China and naturally grows on an area of ​​5.5 to 6 million hectares and is cultivated on an area of ​​275,000 hectares (as of 2010). The wood is used as firewood, as logs for posts, power and telephone lines, as construction timber , for fences and gates and as packaging for transport. It is used to make furniture, plywood , pulp and cellulose . Turpentine is obtained from the resin and tannins from the bark . The needles are used as fodder or distilled to make oil and medicinal products. Trees are also planted as windbreaks and to protect against erosion. In China it is also a popular ornamental tree , but is rarely planted in other countries, with the exception of arboretums . It is a pioneer plant that can show invasive behavior.

swell

literature

  • Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 782-784 .
  • 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. 15 (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

  1. ↑ a b c d e Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 782
  2. ↑ Christopher J. Earle: Pinus yunnanensis. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed March 9, 2013 .
  3. ↑ a b c Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus yunnanensis , in Flora of China , Volume 4, p. 15
  4. ^ Tropicos. [1]
  5. ↑ a b c d e f Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 783
  6. ↑ Pinus yunnanensis in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed March 9, 2013.
  7. ↑ Pinus yunnanensis. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture, accessed March 9, 2013 .
  8. ↑ To be precise: Etymological dictionary of botanical plant names. P. 487
  9. ^ Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus yunnanensis var.yunnanensis , in Flora of China , Volume 4, p. 15
  10. ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 783-784
  11. ↑ Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus yunnanensis var.pygmaea , in Flora of China , Volume 4, p. 15
  12. ↑ Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus yunnanensis var.tenuifolia , in Flora of China , Volume 4, p. 15
  13. ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 782-783

Web links

Commons : Pinus yunnanensis  - collection of images, videos and audio files