Koyama spruce
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Koyama spruce ( Picea koyamae ) |
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The Koyama spruce ( Picea koyamae ) is a species from the pine family (Pinaceae). It is a relic species native to Japan.
description
The Koyama spruce grows as an evergreen tree that can reach heights of growth of up to 20 meters and diameters of up to 40 centimeters at chest height . The thin branches go off horizontally from the straight trunk. The trunk bark is smooth and brown in color in young trees. It changes color from gray-brown to black-brown with age, becomes rough and flaky and flakes off in thin scales. The hairless, furrowed bark of the branches is brown in color.
The strong pulvini are 0.8 to 0.9 millimeters long. The light green needles are 0.8 to 1.2 centimeters long and around 0.15 centimeters wide and are linear-square in shape. Its tip is pointed on young trees and blunt on older trees. There is a conspicuous stoma band on each needle side .
The Koyama spruce is single-sexed ( monoecious ) and the flowering period extends from May to June. The cylindrical male cones are reddish brown in color and have numerous stamens . The cones hanging individually from the branches are cylindrical in shape, 4 to 8 centimeters long and 2 to 2.5 centimeters thick. They are reddish purple in color when ripe. The thin and woody seed scales are spherical to egg-shaped and are about 1.5 inches long and 1.3 to 1.6 inches wide. Their upper edge is finely serrated. The spindle-shaped, black-brown seeds are about 3 millimeters long and about 2 millimeters wide. They have a light brown, elongated to obovate wing, which is about 1 inch long and about 0.5 inches wide.
The number of chromosomes is 2n = 24.
Distribution and location
The natural range of the Koyama spruce is in Japan. It includes the Yatsugatake Mountains and the Akaishi Mountains in central Honshū . It is considered a relic species that occurs on the southern border of the spruce distribution area.
The Koyama spruce thrives at altitudes of 1500 to 2000 meters. It is a tree species of cool climate with snowy winters. The annual rainfall is between 1000 and 2000 millimeters, depending on the location. It grows mainly on northern slopes on cooled lava flows or on soils that have formed on phyllite , sandstone or limestone. The species forms both pure and mixed stocks. The associated species include the Japanese larch ( Larix kaempferi ), the Alcocks spruce ( Picea alcoquiana ), Maximowicz's spruce ( Picea maximowiczii ), the Korean pine ( Pinus koraiensis ), the Mongolian oak ( Quercus mongolica ) and the Japanese arborvitae ( Thuja standishii ) as well as various shrubs.
The Koyama spruce is classified as "Critically Endangered" on the IUCN Red List . The current range of the species covers less than 100 km² and the total population is estimated at fewer than a thousand fully grown trees. In particular, forest fires, typhoons as well as landslides and forest felling in connection with planting of Japanese larch have led to the fact that there are only relatively small, isolated stands between which there is little gene exchange. The number of mature trees is considered to be declining.
Systematics
Picea koyamae is assigned to the subgenus Picea , the section Picea , the subsection Picea and the series Picea within the genus of the spruce trees ( Picea ) .
The first description as Picea koyamai was in 1913 by Homi Shirasawa in Botanical Magazine , Volume 27, Page 128. The specific epithet koyamae honors the botanist Mitsua Koyama (1885-1935), who discovered the species in 1911.
swell
- Christopher J. Earle: Picea koyamae. In: The Gymnosperm Database. www.conifers.org, November 28, 2012, accessed on July 28, 2013 (English).
- T. Yamazaki: Picea koyamae. In: Flora of Japan. www.foj.cu-tokyo.ac.jp, accessed on July 28, 2013 (English).
Individual evidence
- ↑ a b c d e f Christopher J. Earle: Picea koyamae. In: The Gymnosperm Database. www.conifers.org, November 28, 2012, accessed on July 28, 2013 (English).
- ↑ a b Picea koyamae at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed August 1, 2016.
- ↑ T. Yamazaki: Picea koyamae. (No longer available online.) In: Flora of Japan. www.foj.cu-tokyo.ac.jp, archived from the original on July 22, 2012 ; accessed on July 28, 2013 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b Picea koyamae in the Red List of Threatened Species of the IUCN 2013. Posted by: T. Katsuki & M. Gardner, 2010. Accessed July 28, 2013.
- ↑ Picea koyamae. In: The Plant List. www.theplantlist.org, accessed on July 28, 2013 .
