Pinus amamiana
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| Pinus amamiana | ||||||||||||
| Koidz. |
Pinus Amamiana is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). This endemic occurs only on two islands in southern Japan. It is classified as "critically endangered" inthe IUCN Red List .
description
Appearance
Pinus amamiana grows as an evergreen tree and reaches heights of 20 to 30 meters. The trunk reaches diameters of up to 2 meters at chest height . The trunk bark of young trees is smooth and gray-brown, in older trees it tears open and breaks in the lower part of the trunk into large, flaking, gray to black-gray plates. The branches of young trees are arranged in false whorls and form a conical treetop. Later it widens to a round open crown. Needled branches are smooth. The young shoots are hairy and fluffy and soon bald, initially gray-green and later gray-brown.
Buds and needles
The vegetative buds are cylindrical and slightly resinous. Terminal buds are 10 to 15 millimeters long, lateral ones are shorter. The scale leaves are reddish brown and ovate-linear.
The needles grow in groups of five in a sheath of thin scales that soon falls off. The needles are thin, protruding, straight or slightly curved, rarely only 3, mostly 5 to 8 and sometimes up to 9 centimeters long, triangular in cross-section and 0.8 to 1 millimeter wide. Only the adaxial sides show stomata lines . Three resin channels are formed per needle . The needles stay on the tree for two to three years.
Cones and seeds
The pollen cones grow spirally in long groups at the base of young shoots. The pollen cones are 1.5 to 2.5, rarely up to 3 centimeters in length, cylindrical or ovoid-elliptical, thin or strong, greenish white with a slightly reddish upper end.
The seed cones grow individually or in pairs, initially green and upright and later dark purple-brown and more and more pendulous on strong, curved, 1 to 2 centimeters long stems. The cones are often resinous, open only a little, are 5 to 7 centimeters long and 3 to 4 centimeters in diameter when opened. The seed scales are woody, stiff, slightly curved inward, 1.5 to 2 inches long and 2 to 3 inches wide. Basal scales, however, are barely curved. On the adaxial side there are two depressions in which the seeds grow. The apophysis is rhombic, or more or less rounded on the outside, light yellowish brown to darker reddish brown, thick woody with a straight or slightly curved edge that ends in the inconspicuous and blunt umbo .
The gray to almost black seeds are ellipsoidal, 10 to 12 millimeters long, 5 to 6 millimeters wide and about 4 millimeters thick, wingless, sometimes with a small crest on the abaxial edge or rarely with a rudimentary wing.
Distribution and locations
The natural range of Pinus amamiana is on the two Japanese islands of Yakushima and Tanegashima , which are south of Kyūshū . There this endemic grows in open stands exposed to the weather in otherwise often hardly overgrown areas on rocky slopes. On Yakushima they are found at altitudes of 250 to 900 meters, on Tanegashima at altitudes of 50 to 200 meters.
Hazard and protection
In the IUCN Red List of the IUCN in 2010 Pinus Amamiana out as "high risk" (= "Endangered"). The area ("extent of occurrence") extends only over 600 square kilometers, there are only four known sites and the stocks together cover only about 50 square kilometers ("area of occupancy"). Yakushima has three populations , one in Seibu with 2000 to 3000 tree specimens, one in Hirauchi with less than 1000, and one in Takahira with less than 100 individuals. In Tanegashima there is only one population in the middle of the island with around 300 fully grown trees. However, all stocks are falling. The trees used to be felled for the wood. Roundworms (Nematoda) accidentally introduced from the United States also cause young specimens to die. Full-grown trees are also affected on Tanegashima. The stocks on Yakushima are located in a protected area.
Systematics
The first description of Pinus amamiana was in 1924 by Gen'ichi Koidzumi in Botanical Magazine, Tokyo , Volume 38, page 113. The specific epithet amamiana is derived from the Amami people who inhabit the Ryūkyū Islands . Farjon 2010 confirms the rank of a species.
The species Pinus amamiana belongs to the sub-section Strobus from the section Quinquefoliae in the sub-genus Strobus within the genus Pinus . 1974 Sumihiko suggested Hatusima in Memoirs of the Faculty of Agriculture; Kagoshima University , 1, page 37, it as a variety Pinus armandii var. Amamiana (Koidz.) Hatus. assigned to the species Pinus armandii . James E. Eckenwalder followed suit in 2009 . The degree of relationship between the species Pinus amamiana and Pinus armandii , Pinus fenzeliana and Pinus morrisonicola has not yet been sufficiently investigated. Pinus amamiana is likely to differ most from the other species by its rather small cones and wingless seeds, which are adapted to be spread by birds. On the other hand, it is known from other pine species such as Pinus albicaulis and Pinus cembra that these adaptations can develop very quickly through selective pressure and are therefore not good indicators of the relationships.
use
Pinus amamiana is not used economically. In the past, the wood was used by the local population as construction timber and for carpentry work. Pinus amamiana is also rarely cultivated, but a little more common in Japan.
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 978-90-04-17718-5 , pp. 609, 619-620 .
- James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 411 .
- Hideaki Ohba: 764. PINUS AMAMIANA Pinaceae. In: Curtis's Botanical Magazine , Volume 30, Issue 3, 2013, pp. 158-165. doi : 10.1111 / curt.12032
Individual evidence
- ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, pp. 619-620
- ↑ a b c d e f g h Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 620
- ↑ a b James E. Eckenwalder: Conifers of the World , p. 411
- ↑ a b c Christopher J. Earle: Pinus bungeana. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed April 30, 2019 .
- ↑ a b c Pinus amamiana in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved April 30, 2019.
- ↑ a b Pinus amamiana in the endangered Red List species the IUCN 2013 Posted by: T. Katsuki, A. Farjon, 2010. Accessed April 30 of 2019.
- ↑ Pinus amamiana at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed April 30, 2019.
- ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 619
- ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 609
