Pinus bhutanica
Pinus bhutanica is a large evergreen coniferous tree of the genus pine (Pinus ) with five of growing, mostly 15-24 cm long needles. The seed pin reach a length 12 to 20 centimeters. The natural range is located in Bhutan, in the northeast of India and in the southwest of China. The species was first described in 1980, above the trees of the tears pine ( Pinus wallichiana ) were attributed. Pinus bhutanica is classified as endangered in the IUCN Red List. The wood is not used, individual trees, however, were introduced in 1979 in the UK, where to find them and also in Ireland in botanical gardens and arboretums.
- 5.1 Literature
- 5.2 Notes and references
Description
Appearance
Pinus bhutanica grow as evergreen tree reaching a height of up to 25 meters and more. The trunk is straight and columnar, reaching a diameter at breast height of up to 80 centimeters. The Stammborke young trees and the bark of the branches is light gray-brown and smooth. The Stammborke older trees is gray-brown and breaks into small, separated by shallow furrows scales that flake off in small parts. The branches are whorled, they are far more expansive and bent. The higher order branches are hanging with upturned ends and form a narrow conical, more or less open crown. The needled branches are brown, thin or rich. Young shoots are hairy glandular in the first year and white frosting, the second year they have a thin, pale gray-green bark.
Buds and needles
The vegetative buds are ovate - conical and slightly resinous. Terminal buds are 10 to 15 millimeters long, which are smaller and more ovate seitständigen. The Lower leaves are gray with an orange tint or light reddish brown. The needles grow in an early fifth- sloping, often only 1.8 usually 2 to 3 mm long, basal needle sheath of delicate, orange-brown scales. The needles are mounted, often curved only at the base and usually straight, very thin and flexible, rarely over 12 usually 15 to 24, and sometimes up to 28 inches long and 1 mm wide with a triangular cross-section. The needle edge is very finely serrated. The color of the leaves is light green on the abaxial side, on the adaxial side Glauk white. The two adaxial sides carry four to seven thin gap opening lines. Are formed near the surface three to four resin canals. The needles remain 1.5 to 2 years on the tree.
Cones and seeds
The pollen cones grow spirally arranged in small groups at the base of young shoots. The yellow at maturity 10 to 20 millimeters long and short cylindrical pin are thereby partially covered by eight to twelve permanent shed leaves.
The seed cones grow singly or in pairs up to sixth in whorls, initially erected and later hanging on strong, often from one usually 4 to 6 inches long stalks. The cones are cylindrical, often slightly curved, 12 to 20 inches long. They have closed diameter 3-4 cm and mature and open diameter 5-7 cm. They are usually resinous and fall soon after the delivery of the seeds along with the stem from. The 60-80 seed scales are dull red-brown, wedge-shaped -oblong, broadest just below the apophysis, thin woody and little flexible. They have two recesses, which contain the seeds at the base adaxial. The apophysis is rhombic, 1 to 1.5 centimeters long and 1.5 to 2.5 centimeters wide, slightly raised, dull keeled, with a more or less pointed end and light brown. The umbo is terminal and is darker than the apophysis.
The seeds are brown, obovate, slightly flattened, 6-8 mm long and 4-5 mm wide. The seed wing is gray-brown, change, 15 to 22 mm long and 7-10 mm wide.
Distribution, ecology and hazard
The natural range of Pinus bhutanica located in Bhutan, in the district of Kameng in the state of Arunachal Pradesh in northeastern India and in the northwest of Yunnan Province and to the southeast of the Tibet Autonomous Region in southwest China. From herbarium specimens, you can close to a variety of forest types in which it occurs, including forests of different species of pine, oak-pine forests, deciduous forests and secondary forests. Typically, it occurs together with evergreen deciduous trees in moist mountain forests, but their best growth it has under somewhat drier conditions. To the west of Bhutan and West Kameng you can find them along with the tears pine ( Pinus wallichiana ). In the Rong Chu Valley in China it grows in pure stands on steep rocky slopes. There are no findings from Myanmar, but are based on the known distribution area stocks likely in Kachin. One finds Pinus bhutanica from heights of 1000 meters in India up to altitudes of 2300 meters in Tibet. There are also reports of stocks altitude of 750 meters and 2750 meters altitude. The distribution area can probably be attributed to the Hardiness Zone 8, with mean annual minimum temperatures -12.1 to -6.7 ° C (10 ° to 20 ° Fahrenheit ).
The IUCN Red List is classified as Pinus bhutanica not endangered ( "Least Concern" ). The holdings in Bhutan, India and Tibet go back much, there are at least 700 square kilometers inhabited (area of occupancy ). Despite the rather rare occurrence the stocks do not appear to be at risk because stocks of tears pine and are easier to achieve roxburghii Pinus by timber harvesting.
Systematics and history of research
Pinus bhutanica is a species in the genus of pine (Pinus ), in which it is assigned to the subgenus strobus, Quinquefoliae section, sub-section strobus. The species was first described in 1980 by Andrew John Charles Grierson, David Geoffrey Long and Christopher Nigel Page in Notes from the Royal Botanic Garden, Edinburgh. The genus name Pinus was already used by the Romans for several pine species. The specific epithet refers to the bhutanica Bhutan, specimens from this area were first described.
Trees of the species previously assigned to tears pine trees ( Pinus wallichiana ). It could have been attributed to bhutanica the tears pine even Herbarium Specimens of Pinus, since the two species mainly differs in appearance and in the form of not always collected young shoots. Pinus bhutanica has longer and stronger hanging needles with a slightly different arrangement of the resin canals, cones and seeds are very similar. Some authors therefore expect the representatives of the species Pinus wallichiana subsp as subspecies. bhutanica ( Grierson, DGLong & CNPage ) Businský Pinus wallichiana to.
Use
About a use of wood is not known. Pinus bhutanica was introduced in Britain in 1979 and thrives in the south of England and Ireland well. Despite their attractive appearance and graceful drooping needles limits the culture of botanical gardens and arboretums kind.