Western Balsam Poplar, Black cottonwood

Populus trichocarpa

Physical Characteristics

Populus trichocarpa is a deciduous Tree growing to 40 m (131ft) by 12 m (39ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from April to May, and the seeds ripen from May to June. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Wind. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid soils. It cannot grow in the shade. It prefers moist soil.

Distribution

Western N. America - Alaska to Oregon.

Habitats

Woodland Garden Canopy;

Edible Uses

Edible Parts: Flowers Inner bark Sap Edible Uses: Inner bark - raw or dried. It is usually ground into a powder and used as a flour, this is normally mixed with other flours for making bread etc[172, 177]. It is best used in the spring[172]. The inner bark is mucilaginous[257] and extremely sweet, but it sours or ferments rapidly and so, unlike most inner barks, it cannot be dried for winter use, though it can be sun-dried for more immediate use[256]. Catkins - raw or cooked. A bitter flavour[172]. Sap - used for food[257].

Medicinal Uses

Anodyne Antiinflammatory Antiscorbutic Antiseptic Balsamic Diuretic Expectorant Febrifuge Stimulant Tonic 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[257]. 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 odour and a bitter taste[213]. They also contain salicin, a glycoside that probably decomposes into salicylic acid (aspirin) in the body[213]. The buds are antiscorbutic, antiseptic, balsamic, diuretic, expectorant, stimulant and tonic[4, 226, 238]. 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[238]. Externally, the buds are used to treat colds, sinusitis, arthritis, rheumatism, muscular pain and dry skin conditions[238]. They can be put in hot water and used as an inhalant to relieve congested nasal passages[213]. The buds are harvested in the spring before they open and are dried for later use[238]. 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[213, 238]. 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[238].

Known Hazards

None known