Pinus tropicalis
Pinus tropicalis is an evergreen coniferous tree of the genus pine (Pinus ). The distribution area is located in western Cuba and on Isla de la Juventud a neighboring island of Cuba. Where it grows in the lowlands at altitudes up to 300 meters. It is not endangered and is used for forestry because of their timber.
- 6.1 Literature
- 6.2 Notes and references
Description
Habit
Pinus tropicalis is up to 30 meter high trees with trunk diameters of up to 1.8 meters. The stem is erect and geradschaftig. The bark is thick, rough, scaly, gray reddish brown and weather influence. She breaks into irregularly shaped plates that are separated by deep, longitudinal cracks in the lower trunk. The branches are ascending or spread out and form an irregular, open crown. The branches are thick, very rough, in the first and second year of glossy orange - brown and gray later.
Buds and needles
The Lower leaves are subulate, recurved, scaly and brown. The leaf buds are ovate -oblong, pointed and have recurved bud scales. Terminal buds are 15 to 25 millimeters long, lateral buds are shorter and not resinous. The needles grow in pairs or threes rare in the beginning about 20 millimeters long, lasting needle sheaths which shorten to 10 mm later. The needles stay two years at the tree, they are very uniform, straight and stiff, sometimes 15 most 20 to 30 millimeters long and 1.5 millimeters thick, sawn, pointed, light green or yellowish green. On all sides of the needle, there are six to eight stomatal strips. The needle two to nine resin ducts are formed.
Cones and seeds
The pollen cones are oblong- ovate to cylindrical, 2-3 cm long with diameters of about 5 millimeters. They are initially pink and later yellowish and then brown. The seed cones are individually, in pairs or in whorls of up to 6 near the ends of branches on short and thick stems. You stand upright or slightly inclined. Young cones are purple about 10 millimeters long with diameters of 5-7 mm. They mature within two years. Mature cones are closed narrowly ovate to ovate narrowed, open egg-shaped with a flattened base. They are then 5 to 8 inches long and 4 to 5.5 inches wide, several years remain on the tree and fall off with the stem. The 100 to 120 dark brown seed scales are oblong, straight or sharply bent. The apophysis is flat or slightly elevated, transversely keeled, rhomboid, striped to pentagonal, radial and light reddish brown. The seeds are distinctly ovate, somewhat flattened, 5 mm long and 4 mm wide, pale gray-brown. The seed wing is 12 to 15 millimeters long, 5-6 mm wide, yellowish with a black or gray tint.
Seedlings initially show a reduced height growth combined with a strong growth of the roots, which gives them a grass-like appearance ( "grass stage" ) and represents an adaptation to the frequent fires.
Distribution and habitat requirements
The natural range of Pinus tropicalis is located in the province of Pinar del Río in western Cuba and on Isla de la Juventud a neighboring island of Cuba. It grows in the lowlands in the coastal plains and the adjacent foothills at altitudes from 1 to 150 times to 300 meters on nutrient-poor, sandy or gravelly, well-drained alluvial young. The climate is tropical, with an average annual rainfall of about 1200 millimeters, and long dry periods. They are found partially Pinus caribaea var caribaea along with, but also occurs at higher elevations. Pinus tropicalis often grows in grass -dominated savanna to frequent fires. In this environment it has over Pinus caribaea the advantage to make fire more resistant seedlings, which they also often the only pine species in such habitats.
Endangering
In the IUCN Red List Pinus tropicalis is not as vulnerable ( " Lower Risk / least concern " ) out. It is noted, however, that a reassessment is pending.
Systematics and history of research
Pinus tropicalis is a species of the genus of pine (Pinus ), in which it is assigned to the subgenus Pinus, section Pinus and Pinus subsection. It was first described in 1851 by Pierre Marie Arthur Morelet in the Revue de la Cote- d'Or Horticole. However, the material used for the first description Aljos Farjon and Brian Styles therefore lost, certain 1997 Material from a collection by Nathaniel Lord Britton of 1916 as neotype. The species was described in 1865 by Charles Henry Wright as Pinus terthrocarpa (synonym ) one more time, taking the 1866 var from August Grisebach as Pinus cubensis terthrocarpa variety described on species status lifted.
The genus name Pinus was already used by the Romans for several pine species. The specific epithet refers to the tropicalis tropical circulation area of the Art
Use
Pinus tropicalis in Cuba is an important supplier of timber, which is further processed in local sawmills. The wood is hard and durable but also resinous. Despite the heavy use it is still widespread and the stocks may be at least well off regenerate pastures. It is so, forestry cultivated in Cuba and to a lesser extent outside of Cuba in the Chinese province of Guangdong.