| Blue Pine | |
|---|---|
| Tree at Tortworth Court arboretum | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Pinaceae |
| Genus: | Pinus |
| Subgenus: | Strobus |
| Species: | P. wallichiana |
| Binomial name | |
| Pinus wallichiana A. B. Jacks. |
|
Pinus wallichiana is a pine native to the Himalaya, Karakoram and Hindu Kush mountains, from eastern Afghanistan east across northern Pakistan and India to Yunnan in southwest China. It grows at high altitudes in mountain valleys at altitudes of 1800–4300 m (rarely as low as 1200 m), and is a tree from 30–50 m in height. It grows in a temperate climate with dry winters and wet summers.
This tree is often known as 'Bhutan Pine', (not to be confused with the recently-described Pinus bhutanica, a closely related species), and also as 'Blue Pine' and as 'Himalayan White Pine'. In the past, it was also known by the invalid botanic names "Pinus griffithii" McClelland or "Pinus excelsa" Wall., and was also known as "Pinus chylla" Lodd. when the tree became available through the European nursery trade in 1836, nine years after Dr Wallich first introduced seeds to England.
The leaves ("needles") are in fascicles (bundles) of five and are 12–18 cm long. They are noted for being flexible along their length, and often droop gracefully. The cones are long and slender, 16–32 cm, yellow-buff when mature, with thin scales; the seeds are 5–6 mm long with a 20–30 mm wing.
Typical habitats are mountain screes and glacier forelands, but it will also form old growth forests as the primary species or in mixed forests with deodar, birch, spruce, and fir. In some places it reaches the tree line.
The wood is moderately hard, durable and highly resinous. It is a good firewood but gives off a pungent resinous smoke. It is a commercial source of turpentine which is superior quality than that of P. roxburghii but is not produced so freely.
It is also a popular tree for planting in parks and large gardens, grown for its attractive foliage and large, decorative cones. It is also valued for its relatively high resistance to air pollution, tolerating this better than some other conifers.