Pinus pringlei
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| Shaw ex Sargent |
Pinus pringlei is a plant from the genus of pine trees ( Pinus ) within the family of the Pinaceae (Pinaceae). The natural range is in Mexico . The wood is used economically.
description
Appearance
Pinus pringlei grows as an evergreen tree and reaches heights of 20 to 25 meters. The trunk is straight and reaches a chest height diameter of up to 100 centimeters. The trunk bark is thick, rough, reddish-brown to gray-brown and divided into small scale-shaped plates by deep, reddish-brown cracks. The branches are horizontal or overhanging, ascending near the tip and form an open, broadly dome-shaped or irregular crown. The twigs are thick, inelastic, initially rough and only smooth, hairless, reddish brown and bluish overflowing after losing the pulvini .
Buds and needles
The vegetative buds are ovate-oblong to cylindrical and not resinous. Terminal buds are 10 to 15 millimeters long, lateral buds are smaller and ovate-pointed. The lower leaves, which are formed as bud scales, are reddish brown, lanceolate to awl-shaped , 10 to 12 millimeters long and dry-skinned. Older bud scales show a bent back tip.
The needles grow in threes, rarely in groups of four, in a dark red-brown to blackish needle sheath that is up to 20 millimeters long and then shortens to 10 to 15 millimeters. The needles are shiny, yellowish-green, green or glaucous- green, stiff, straight, 18 to 25, rarely from 15 or up to 25 centimeters long and 1.0 to 1.5 rarely up to 1.7 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 narrow stomata lines on all needle sides . Usually four to seven, rarely from three or up to nine resin canals are formed.
Cones and seeds
The pollen cones are yellowish, ovate-oblong to cylindrical and when fully ripe, 1.5 to 2.5 centimeters long with a diameter of about 8 millimeters. The seed cones grow near the ends of branches, singly or more often in whorls of two to four on short, strong, curved stems. Mature cones are open at lengths of 5 to 8, rarely up to 10 centimeters and at diameters from 3.5 to 6, rarely up to 7 centimeters ovoid, slightly curved or asymmetrical. The 50 to 100 seed scales are thick, woody, elongated, almost straight and symmetrical. The apophysis is almost flat to slightly raised on the inner side of the cone, protruding a little more on the outer side, transversely keeled, rhombic to pentagonal in outline, shiny ocher or light brown. The umbo is flat or sunk and reinforced with a small, sloping spike .
The dark brown to gray-brown seeds are obovate and 4 to 6 millimeters long. The seed wing is 14 to 18 millimeters long, 6 to 8 millimeters wide, translucent and light brown.
Occurrence and endangerment
The natural range of Pinus pringlei is in the Mexican states of Michoacán , México , Morelos , Guerrero and Oaxaca , possibly also in western Puebla .
Pinus pringlei grows in the subtropical to warm temperate climate in montane forests of the Sierra Madre del Sur and in parts of the Sierra Volcánica Transversal at altitudes of 1500 to 2600, sometimes up to 2800 meters. The distribution 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 1000 to 2000 millimeters, with the largest part falling in summer thunderstorms between June and September. The forests are mostly pine forests or mixed forests of pine and oak , in which the species is found together with Pinus douglasiana , Pinus patula , Pinus maximinoi , Pinus oocarpa and Pinus pseudostrobus . In drier areas, often with secondary forests, they are more often found with Pinus lawsonii and Pinus devoniana .
In the Red List of the IUCN is Pinus pringlei as "not at risk" (= "Lower Risk / least concern") classified. However, it should be noted that a reassessment is necessary.
Systematics
The first description of Pinus pringlei was in 1905 by George Russell Shaw in the work of Charles Sprague Sargent : Trees and Shrubs , Volume 1, Part 4, Page 211, Plate 100. The specific epithet pringlei honors the collector Cyrus Guernsey Pringle (1838-1911), who carried out several plant collections in Mexico, and also collected the type specimen of this species. The type material was collected in Michoacán ( "hilltops near Uruapán" ) in 1904 and deposited with the herbarium number Pringle 10019. It was established in 1997 by A. Farjon and BT Styles in Pinus (Pinaceae). established as lectotype material in Flora Neotropica , Volume 75, page 177 . It is one of the few Mexican Pinus species that has no synonyms .
The species Pinus pringlei belongs to the Australes subsection from the Trifoliae section in the Pinus subgenus within the Pinus genus . Pinus pringlei is similar to its two close relatives, Pinus teocote and Pinus herrerae, in terms of the texture of the wood and the three-needle bundles of needles, but Pinus pringlei has thicker and stiffer needles than the other two species.
use
The wood of Pinus pringlei is dense and used as construction timber , the resin is extracted economically. It is not known to be used as an ornamental plant.
swell
literature
- James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 433 .
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 741-742 .
- Aljos Farjon. BT Styles in Pinus (Pinaceae). in Flora Neotropica , Volume 75, Page 177.
Individual evidence
- ↑ a b c d Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 741
- ↑ a b c d e f g h James E. Eckenwalder: Conifers of the World , p. 467
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 741-742
- ↑ a b c d e Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 742
- ↑ a b c Christopher J. Earle: Pinus pringlei. In: The Gymnosperm Database. www.conifers.org, 2019, accessed on April 21, 2019 .
- ↑ Pinus pringlei in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed May 12, 2013.
- ↑ Pinus pringlei at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved April 21, 2019.
Web links
- Vascular Plants of the Americas : Pinus pringlei at Tropicos.org. In: 83 . Missouri Botanical Garden, St. Louis