Pinus tropicalis
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Pinus tropicalis is an evergreen conifer from the genus of pine ( Pinus ). The distribution area is in western Cuba and on Isla de la Juventud , a subsidiary island of Cuba. There it grows in the lowlands at heights of up to 300 meters. It is not endangered and is used for forestry because of its wood.
description
Habitus
Pinus tropicalis forms trees up to 30 meters high with trunk diameters of up to 1.8 meters. The trunk is erect and straight. The bark is thick, rough, scaly, reddish brown and gray when exposed to the weather. It breaks into irregularly shaped plates that are separated by deep, longitudinal cracks in the lower trunk area. The branches are ascending or spread out and form an irregular, open crown. The twigs are thick, very rough, shiny orange-brown in the first and second years and later gray.
Buds and needles
The lower leaves are sub-like , bent back, scale-shaped and brown. The leaf buds are ovate-elongated, pointed and have bent scales. Terminal buds are 15 to 25 millimeters long, side buds are shorter and not resinous. The needles grow in twos or, less often, in threes in permanent needle sheaths that are initially around 20 millimeters long and later shorten to 10 millimeters. The needles stay on the tree for two years, they are very uniform, straight and stiff, sometimes 15, usually 20 to 30 millimeters long and 1.5 millimeters thick, serrate, pointed, light green or yellowish green. There are six to eight stomata opening strips on all sides of the needle . Two to nine resin channels are formed per needle.
Cones and seeds
The pollen cones are elongated-ovoid to cylindrical, 2 to 3 centimeters long with a diameter of about 5 millimeters. They are pink at first and later turn yellow and then brown. The seed cones stand singly, in pairs or in whorls of up to 6 near the ends of branches on short and thick stalks. You stand upright or slightly inclined. Young cones are purple-red about 10 millimeters long with a diameter of 5 to 7 millimeters. They mature within two years. Matured cones are closed, narrowly ovate to narrowed ovoid, open ovoid with a flattened base. They are then 5 to 8 centimeters long and 4 to 5.5 centimeters wide, stay on the tree for several years and fall off with the stem. The 100 to 120 dark brown seed scales are elongated, straight or strongly bent back. The apophysis is flat or slightly raised, transversely keeled, rhombic to pentagonal, radially striped and light to reddish brown. The seeds are clearly egg-shaped, somewhat flattened, 5 millimeters long and 4 millimeters wide and light gray-brown. The seed wing is 12 to 15 millimeters long, 5 to 6 millimeters wide, yellowish with a black or gray tint.
Seedlings initially show reduced height growth combined with strong growth of the roots, which gives them a grass-like appearance (“grass stage”) and is an adaptation to the frequent fires.
Distribution and location requirements
The natural range of Pinus tropicalis is in the province of Pinar del Río in the west of Cuba and on Isla de la Juventud a side island of Cuba. It grows in the lowlands in the coastal plains and on the adjacent mountain foothills at heights of 1 to 150 sometimes up to 300 meters on nutrient-poor, sandy or gravelly, well-drained young alluvial soil . The climate is tropical, with an average annual rainfall of about 1200 millimeters and long dry periods. It is sometimes found together with Pinus caribaea var. Caribaea , which also occurs at higher altitudes. Pinus tropicalis often grows in grass-dominated savannas with frequent fire. In this environment it has the advantage over Pinus caribaea that it produces more fire-resistant seedlings, which is why it is often the only species of pine in such habitats.
Danger
In the Red List of the IUCN is Pinus tropicalis be deemed not at risk ( "Lower Risk / least concern"). However, it should be noted that a reassessment is pending.
Systematics and research history
Pinus tropicalis is a species of the genus of pine ( Pinus ), in which it is assigned to the subgenus Pinus , section Pinus and subsection Pinus . It was in 1851 by Pierre Marie Arthur Morelet in Revue Horticole de la Cote-d'Or first described . However, the material used for the first description was lost, so Aljos Farjon and Brian Styles designated material from a collection by Nathaniel Lord Britton from 1916 as a neotype in 1997 . The species was in 1903 by Shaw once more as art named Pinus terthrocarpa ( synonym described) a second time so that he, the 1866 August Grisebach as Pinus cubensis var. Terthrocarpa described variety lifted species status.
The generic name Pinus was already used by the Romans for several types of pine. The specific epithet tropicalis refers to the tropical range of the species.
use
Pinus tropicalis is an important supplier of wood in Cuba, which is processed in local sawmills. The wood is heavy and durable but also resinous. Despite the heavy use, it is still widespread and the populations can regenerate well, at least away from pastureland. It is cultivated for forestry in Cuba and, to a lesser extent, outside of Cuba, for example in the Chinese province of Guangdong .
swell
literature
- Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 90-04-17718-3 , pp. 776, 777 .
- Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China . Volume 4: Cycadaceae through Fagaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 1999, ISBN 0-915279-70-3 , pp. 20 (English).
- 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).
Individual evidence
- ↑ a b c Liguo Fu, Nan Li, Thomas S. Elias, Robert R. Mill: Pinus tropicalis , in Flora of China , Volume 4, p. 20
- ↑ a b c Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 776
- ^ A b Christopher J. Earle: Pinus tropicalis. In: The Gymnosperm Database. www.conifers.org, November 23, 2012, accessed February 9, 2013 .
- ^ Aljos Farjon: A Handbook of the World's Conifers , Volume 2, pp. 776-777
- ↑ a b c Aljos Farjon: A Handbook of the World's Conifers , Volume 2, p. 777
- ↑ Pinus tropicalis in the endangered Red List species the IUCN 2012. Posted by: Conifer Specialist Group, 1998. Accessed February 7, 2013.
- ↑ Pinus tropicalis. In: Germplasm Resources Information Network (GRIN). United States Department of Agriculture, accessed February 7, 2013 .
- ↑ Rafaël Govaerts (ed.): Pinus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved April 17, 2019.
- ↑ To be precise: Etymological dictionary of botanical plant names. P. 487
Web links
- Pinus tropicalis. In: The Plant List. Retrieved February 7, 2013 .