Pinus oocarpa
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Pinus oocarpa in El Salvador |
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| Differences ex Schlechtendahl |
Pinus oocarpa is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). The natural range is in Mexico and in several states of Central America. The wood and also the resin are used economically, and this species has been introduced and grown for forestry in several countries in Africa and South America.
description
Appearance
Pinus oocarpa grows as an evergreen tree that reaches heights of 30 to 35 meters. The upright trunk reaches a chest height diameter of 100 to 130 centimeters.
The trunk bark is thick, rough, scaly, dark brown to gray-brown and breaks into small and large, elongated plates and shallow cracks. The branches are long, often twisted, spread out and form a rounded or irregular open crown. Young shoots are reddish brown, rough, hairless and scaly.
Buds and needles
The vegetative buds are ovate-oblong or funnel-shaped and not resinous. Terminal buds are 15 to 25 millimeters long, lateral buds are smaller and ovate-pointed. The formed as bud scales low sheets are brown, under influence of weather blackish gray, trockenhäutig, pfriemförmig , 10 to 15 millimeters long and bent back.
The needles grow in groups of four or five in a needle sheath that is up to 25 millimeters long, does not shorten, is red-brown and, when exposed to the weather, almost black. The needles are shiny, yellowish green to green, straight, stiff or less often flexible, 14 to 25 centimeters, rarely from 11 and up to 30 centimeters long and 0.8 to 1.6 millimeters thick. They stay on the tree for two to three years. The edge of the needle is finely sawn, the end pointed and piercing. There are stomata lines on all needle sides . Four to eight resin channels are formed.
Cones and seeds
The pink to reddish pollen cones are elongated-cylindrical with a length of 1.5 to 2 centimeters and with a diameter of 5 to 6 millimeters. The seed cones grow near the ends of twigs, singly or in twos or four in whorls on strong, up to 35 millimeters long, bent stems that can stay on the cones when they fall off. The cones remain on the tree for several years after the seeds have been released. Ripe cones are 3 to 8, rarely up to 10 centimeters in length and 3 to 9, rarely up to 12 centimeters in diameter, ovoid to almost spherical, often wider than they are when opened, with a flattened base. The 40 to 100, rarely up to 130, seed scales are thick, woody, symmetrical, elongated, straight or slightly bent back. The apophysis is almost flat or slightly protruding, in some cones pyramidal, slightly cross keeled, with a rhombic or pentagonal outline, glossy, ocher-colored or light brown and gray when exposed to the weather. The umbo is flat or protruding, sometimes curved, blunt, or rarely armed with a small spine .
The seeds are obliquely ovoid, slightly flattened, 4 to 8 millimeters long, 3 to 4.5 millimeters wide, blackish gray and often spotted with black. The seed wings are 8 to 18 millimeters long, 4 to 8 millimeters wide and gray-brown.
Occurrence and endangerment
The natural range of Pinus oocarpa extends from Mexico to some Central American states. In Mexico you can find them in the southeastern Sierra Madre Occidental , in southern Sonora , in Sinaloa , in southwest Durango , in Nayarit , in southern Zacatecas , in Jalisco , Michoacán , México and Hidalgo , in northern Puebla , in Morelos , Tlaxcala , Guerrero , Nayarit, Oaxaca , in southern Veracruz , Chiapas and in the Ciudad de México. It is widespread in the highlands of Guatemala and can be found in Honduras , El Salvador and northwestern Nicaragua .
The distribution area extends over about 3000 kilometers from northwest to southeast over different climatic zones. Pinus oocarpa grows at altitudes of mostly 500 to 2300 (from 200 to 2700) meters. The natural area is assigned to winter hardiness zone 9 with mean annual minimum temperatures between −6.6 ° and −1.2 ° Celsius (20 to 30 ° Fahrenheit ). The annual rainfall ranges from 700 to 3000 millimeters. Much of the range has a dry spell from October to June and regular fires are part of the natural ecosystem, but man-made fires are now much more common. The species is adapted to the regular fires and the discharge of the seeds is influenced by the fire. It usually grows in open woodland or in forests, often in pure stands or in mixed forests of pines and oaks . Other pine trees commonly found with Pinus oocarpa are Pinus engelmannii , Pinus leiophylla , and Pinus douglasiana in the northwest and Pinus maximinoi , Pinus devoniana and Pinus tecunumanii in the southeast of the range. If fires are less frequent, the undergrowth consists, for example, of representatives of the powder puffy bushes ( Calliandra ), the acacia ( Acacia ), the genera Leucaena , Hybosema and Byrsonima and the grape heather ( Leucothoe ), with frequent fires from bracken ( Pteridium aquilinum ) and grasses.
In the Red List of the IUCN is Pinus oocarpa "not at risk" (= "Lower Risk / least concern") classified. However, it should be noted that a reassessment is necessary. However, the frequent man-made fires can threaten the development of adult populations. This is especially true in Central America, where fires or infestation by the bark beetle Dendroctonus mexicanus often lead to the conversion of forests into grasslands.
Systematics
The first description of Pinus oocarpa was in 1838 by Christian Julius Wilhelm Schiede in Diederich Franz Leonhard von Schlechtendal : Linnaea , Volume 12, Pages 491-492. The specific epithet oocarpa comes from Latin and means something like "egg fruit", this refers to the shape of the unopened sperm cones, which is similar to eggs. Synonyms for Pinus oocarpa Schiede are: Pinus oocarpoides Lindl. ex Loudon , Pinus oocarpa var. oocarpoides (Lindl. ex Loudon) Finisher , Pinus oocarpa var. manzanoi Martínez .
The species Pinus oocarpa belongs to the Australes subsection from the Trifoliae section in which it belongs to the Pinus sub-genus within the Pinus genus .
Pinus oocarpa can easily be confused with the closely related species Pinus praetermissa and Pinus tecunumanii . It can form hybrids with Pinus patula , but no natural hybrids have been identified. Sometimes, however, the long stalks of the seed cones of Pinus patula in the south of their range, in which both species occur, are attributed to a hybridization with Pinus oocarpa . Hybridization could also explain areas in which Pinus oocarpa forms groups of three needles instead of the usual five needles. There have been reports of natural hybrids with the Caribbean pine ( Pinus caribaea ) from Honduras, but these are dubious as the artificial crossing of the two species is extremely difficult.
use
In the entire distribution area, Pinus oocarpa is an important supplier of wood. The wood is of a better quality than that of the Caribbean pine ( Pinus caribaea ), it is stronger and less resinous. It is used for carpentry and joinery work and for the production of floors, other areas of application are as railway sleepers and telephone poles . The abbreviation as commercial timber according to EN 13556 is PNOO. Pinus oocarpa is also widely resinated , with resin only being done in the last few years before felling. The species was introduced and planted for forestry in several tropical and subtropical regions, for example in West Africa and South Africa, in Brazil, Colombia and Argentina. It is very rare in gardens and is limited to a few botanical gardens and arboretums in countries with a warm climate.
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 726-727 .
- James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 437 .
Individual evidence
- ↑ a b c d e f g Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 726
- ↑ a b c d e f James E. Eckenwalder: Conifers of the World , p. 458
- ↑ a b c Pinus oocarpa in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved May 18, 2013.
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 726-727
- ↑ Pinus oocarpa in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed May 17, 2013.
- ^ A b Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 727
- ↑ Pinus oocarpa at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved April 21, 2019.
- ↑ a b Christopher J. Earle: Pinus oocarpa. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed May 18, 2013 (English).
- ↑ James E. Eckenwalder: Conifers of the World , p. 459
- ↑ 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).
- ↑ James E. Eckenwalder: Conifers of the World , pp. 458-459
Web links
- Vascular Plants of the Americas : Pinus oocarpa at Tropicos.org. In: 83 . Missouri Botanical Garden, St. Louis