Pinus torreyana
| Pinus torreyana | ||||||||||||
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Pinus torreyana in Torrey Pines State Park , La Jolla , San Diego , California |
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| Scientific name | ||||||||||||
| Pinus torreyana | ||||||||||||
| Parry ex Carrière |
Torrey Pine is a plant from the genus of pine trees ( Pinus ) within the family of Pinaceae (Pinaceae). The natural range is in California. A distinction is made between two subspecies, the range of one subspecies is north of San Diego from the sea to about 1.5 kilometers inland, the range of the second subspecies is on the island of Santa Rosa Island . With fewer than 5000 specimens, it is the rarest species of pine in North America. The species is protected by law and is classified as endangered inthe IUCN Red List due to its low population.
description
Appearance
Pinus torreyana grows as an evergreen tree that reaches heights of 15 to 23 meters. The trunk in the natural range is usually crooked or bent and reaches a diameter of up to 100 centimeters at chest height . The trunk bark is rough and scaly, deeply torn into irregular, elongated, flat plates, initially reddish-brown and in older trees purple-gray. The branches are spread or ascending and form an open or flat crown. Needled twigs are strong and about 10 millimeters thick, twigs that carry seed cones are up to 20 millimeters thick. The bark of young twigs is bare, rough, initially greenish and later purple-brown to black.
Buds and needles
The buds are egg-shaped-conical, pale brown, 20 to 30 millimeters long and not resinous. The low leaves, which are formed as bud scales, are light brown and have a white border. The needles usually grow in groups of five, sometimes in groups of four or six, in a needle sheath that is up to 20 millimeters long but shortens later on. They are gray-green, stiff and protruding, straight or curved, slightly twisted around the longitudinal axis, 15 to 25 centimeters long and about 2 millimeters thick. The edge of the needle is very finely sawn, the end suddenly pointed. There are clear stomata lines on all needle sides . Three to six resin channels are formed. The needles stay on the tree for three to four years.
Cones and seeds
The pollen cones are yellow, oval-cylindrical and 20 to 30 millimeters long with a diameter of 8 to 10 millimeters. The seed cones grow singly or rarely in pairs on sturdy, 3 to 4 centimeters long stems. The cones ripen after 3 years and stay on the tree for several years. Ripe cones are very large, broadly ovate to ovoid-conical, 10 to 16 centimeters long and when opened 8 to 17 centimeters wide, yellow to red-brown and very resinous. The 60 to 80 seed scales are thick, woody, stiff and wedge-shaped. They have two adaxial seed cavities. The apophysis is clearly developed and raised, more or less rhombic to polygonal in outline, sharply keeled across or provided with four to five converging furrows, shiny light brown or reddish brown. The umbo lies centrally to dorsally. It is pyramidal or slightly curved and has a blunt and hard tip.
The seeds are large, obovate, slightly flattened, up to 10 millimeters long, 10 to 14 millimeters wide, light brown and sometimes darkly spotted. The seed wing is shortened, up to 10 millimeters long. It surrounds the seed in a ring, often falls off early or remains on the seed scales.
Chromosome number
The number of chromosomes is 2n = 24.
Occurrence and endangerment
The natural range of Pinus torreyana is in southern California in San Diego County and Santa Barbara County .
Pinus torreyana is a tertiary relic species , so it had a much larger distribution area at this time, but was pushed back to a small area along the coast with a width of about 1.6 kilometers and to the small island of Santa Rosa Island off southern California. The distribution area extended in the Oligocene and Miocene further north to what is now Oregon . It grows directly from the sea to a height of about 180 meters on stony and sandy slopes. It needs the afternoon mist, which comes daily from the sea, which weakens the direct sunlight. They can be found in the chaparral or with other trees such as oaks and the American strawberry tree (Arbutus menziesii).
In the Red List of the IUCN is Pinus torreyana as "endangered" (= "Vulnerable") classified. It should be noted, however, that a reassessment is pending.
Systematics and research history
The valid first description of Pinus torreyana was in 1855 by Élie-Abel Carrière in Traité Général des Conifères ... , 1, pages 326–327. This description was based on a description by Charles Christopher Parry , which, however, did not meet the requirements for an initial description. The specific epithet torreyana was chosen by Charles Christopher Parry and is reminiscent of the American botanist John Torrey (1796–1873).
The species Pinus torreyana belongs to the subsection Ponderosae from the section Trifoliae in the subgenus Pinus , within the genus of the pines ( Pinus ).
There are two subspecies of Pinus torreyana :
- Pinus torreyana Parry ex Carrière subsp. torreyana ( syn .: Pinus lophosperma Lindl. ): The trees have an upright trunk, usually 15 meters, less often 20 meters high. The seed cones are closed egg-shaped with a diameter of less than 12 centimeters. The seeds are more or less evenly brown and either not at all or only slightly spotted. The distribution area is in San Diego County on the coast north of San Diego. The southern stocks are legally protected in Torrey Pines State Park . Due to the small number of less than 3500 specimens (status 2010) divided into two populations on around 320 hectares and the proximity to a metropolitan area, the populations are threatened by events such as fires, diseases or insect infestation. Trees outside the park are not protected from urban development and are sometimes felled. An infestation by beetles from the genus Ips was successfully survived. Nevertheless, the subspecies is classified as Critically Endangered by the IUCN .
- Pinus torreyana subsp. insularis J.R. Haller : The trees mostly look crippled and usually only reach heights of less than 10 meters. The crown is flat due to the harsh environmental conditions. When closed, the seed cones are usually wider than 12 centimeters and have strong, almost straight umbos. The seeds are spotted black. The distribution area is on Santa Rosa Island in Santa Barbara County. The stands consist of two populations of around 1000 mature trees on less than 100 hectares. The trees are protected by law, but the stands are close to the coast and are at risk from erosion, fire, insects and disease. The subspecies is therefore by the IUCN as endangered ( Endangered classified).
use
Pinus torreyana is not used as a supplier of wood and the stocks are protected by law. It is used horticultural in California, but rarely outside of California. In the more favorable conditions in gardens, it can grow into a large tree, with one specimen in New Zealand reaching a height of 45 meters and a chest-height diameter of 1.5 meters.
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 774-776 .
- James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 427 .
- Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 2: Pteridophytes and Gymnosperms . Oxford University Press, New York / Oxford a. a. 1993, ISBN 0-19-508242-7 (English).
- Carl L. Hubbs and Thomas W. Whitaker (ed.): Torrey Pines State Reserve. The Torrey Pines Association, La Jolla 1964 (2nd Edition 1972), pp. 27-28.
Individual evidence
- ↑ a b c d e f g h i Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 774.
- ↑ a b c d e Robert Kral: Pinus torreyana Parry ex Carrière - online with the same text as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico. Volume 2: Pteridophytes and Gymnosperms. Oxford University Press, New York and Oxford, 1993, ISBN 0-19-508242-7 .
- ↑ a b c James E. Eckenwalder: Conifers of the World , pp. 486-487.
- ↑ Pinus torreyana at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ↑ a b Pinus torreyana in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed June 23, 2013.
- ↑ Pinus torreyana at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved April 20, 2019.
- ↑ Pinus torreyana in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved April 20, 2019.
- ↑ a b Christopher J. Earle: Pinus torreyana. In: The Gymnosperm Database. www.conifers.org, January 6, 2013, accessed June 23, 2013 .
- ↑ a b Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 776.
- ↑ Pinus torreyana subsp. torreyana in the endangered Red List species the IUCN 2012. Posted by: Farjon, A., 2011. Accessed January 20, 2020th
- ↑ Pinus torreyana subsp. insularis in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed June 23, 2013.
Web links
- Pinus torreyana at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed June 23, 2013.