Common Name :Black cottonwood; Western balsam poplar or California poplar
Habitat : Populus trichocarpa is native to western North America.
Populus trichocarpa is a deciduous broadleaf large tree, growing to a height of 30-50 m and a trunk diameter of over 2 m, which makes it the largest poplar species in the Americas. It is normally fairly short-lived, but some trees may live for up to 400 years (Forbes 2006). A cottonwood discovered in Haines, Alaska set the national record at 101 ft (31 m) tall and 32.5 ft (9.9 m) around.
The bark is grey and covered with lenticels, becoming thick and deeply fissured on old trees. The bark can become hard enough to cause sparks when cut with a chainsaw. The stem is grey in the older parts and light brown in younger parts. The crown is usually roughly conical and quite dense. In large trees the lower branches droop downwards. Spur shoots are common. The wood has a light coloring and a straight grain.
The leaves are 7-20 cm long with a glossy dark green upper side and glaucous light grey-green underside; larger leaves, up to 30 cm long, may be produced on stump sprouts and very vigorous young trees. The leaves are alternate, elliptic with a crenate margin and an acute tip, and reticulate venation (see leaf terminology). The petiole is reddish. The buds are conical, long, narrow and sticky, with a strong balsam scent in spring when they open.
Populus trichocarpa has an extensive and aggressive root system, which can invade and damage drainage systems. Sometimes the roots can even damage the foundations of buildings by drying out the soil.
It is also grown as an ornamental tree, valued for its fast growth and scented foliage in spring, detectable from over 100 m distance. The roots are however invasive, and it can damage the foundations of buildings on shrinkable clay soils if planted nearby (Mitchel 1996).
Branches can be added to potted plants to stimulate rooting
The gum from the buds was used in preparations for baldness, sore throats, whooping cough and tuberculosis. Some tribes placed the gum that exudes from the burls of cottonwood directly on cuts and wounds. Western balsam poplar has a long history of herbal use. It was commonly used by many native North American Indian tribes who valued it especially for its antiseptic and expectorant properties, using it to treat lung complaints, wounds, skin conditions etc. It is still commonly employed in modern herbalism with much the same uses.
The leaf buds are covered with a resinous sap that has a strong turpentine odor and a bitter taste. They also contain salicin, a glycoside that probably decomposes into salicylic acid (aspirin) in the body. The buds are antiscorbutic, antiseptic, balsamic, diuretic, expectorant, stimulant and tonic. They are taken internally in the treatment of bronchitis and upper respiratory tract infections. They should not be prescribed to patients who are sensitive to aspirin. Externally, the buds are used to treat colds, sinusitis, arthritis, rheumatism, muscular pain and dry skin conditions. They can be put in hot water and used as an inhalant to relieve congested nasal passages. The buds are harvested in the spring before they open and are dried for later use.
Although no specific mention has been seen for this species, the bark of most, if not all members of the genus contain salicin, a glycoside that probably decomposes into salicylic acid (aspirin) in the body. The bark is therefore anodyne, anti-inflammatory and febrifuge. It is used especially in treating rheumatism and fevers, and also to relieve the pain of menstrual cramps.
Native American tribes in the Pacific Northwest used P. trichocarpa for a variety of purposes. The inner bark was sometimes eaten but most of its uses were medicinal or practical. Because of its salicin content it was often used raw or in salves to treat a number of ailments including baldness, tuberculosis, rheumatism, and treating wounds. The wood, roots and bark were used for firewood, canoe making, rope, fish traps, baskets and structures. The gum-like sap was even used as a glue or as waterproofing.
Commercial extracts are produced from the fragrant buds for use as a perfume in medicines and cosmetics.
‘P. trichocarpa contains salicin, and has been used medicinally as an antipyretic, analgesic and to control inflammation.
Other Uses: It is used for timber, and is notable as a model organism in plant biology. Its full genome sequence was published in 2006.
P. trichocarpa wood is light-weight and although not particularly strong, is strong for its weight. The wood material has short, fine cellulose fibres which are used in the production of high-quality book and magazine paper. The wood is also excellent for production of plywood. Living trees are used as windbreaks.
Populus trichocarpa grows very quickly; trees in plantations in Great Britain have reached 18 m (59 ft) tall in 11 years, and 34 m (112 ft) tall in 28 years (Mitchell 1996). It can reach suitable size for pulp production in 10–15 years and about 25 years for timber production.
The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.
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