[4] A cottonwood in Willamette Mission State Park near Salem, Oregon, holds the national and world records.

The buds are conical, long, narrow, and sticky, with a strong balsam scent in spring when they open.

Attached to its cotton, the seed is light and buoyant and can be transported long distances by wind and water.

Moist seedbeds are essential for high germination, and seedling survival depends on continuously favorable conditions during the first month.

It is also found inland, generally on the west side of the Rocky Mountains, in British Columbia, southwestern Alberta, western Montana, and north-to-central Idaho.

Black cottonwood grows on alluvial sites, riparian habitats, and moist woods on mountain slopes, from sea level to elevations of 2,100–2,750 m (6,890–9,020 ft).

It often forms extensive stands on bottomlands of major streams and rivers at low elevations along the Pacific Coast, west of the Cascade Range.

In eastern Washington and other dry areas, it is restricted to protected valleys and canyon bottoms, along streambanks, and edges of ponds and meadows.

It grows on a variety of soils from moist silts, gravels, and sands to rich humus, loams, and occasionally clays.

Black cottonwood is a pioneer species that grows best in full sunlight and commonly establishes on recently disturbed alluvium.

Seeds are numerous and widely dispersed because of their cottony tufts, enabling the species to colonize even burn sites, if conditions for establishment are met.

Seral communities dominated or codominated by cottonwood are maintained by periodic flooding or other types of soil disturbance.

[13] It is 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).

[13] The wood, roots and bark have been used for firewood, canoe making, rope, fish traps, baskets and structures.

The Squaxin used the bark for sore throats and for the treatment of tuberculosis, as well as water and the bruised leaves as an antiseptic mixture.

[9] The shredded and heat treated wood is sold a pet snake bedding material, with its softness, water absorbency, and low maintenance described as its primary properties.

The wood material has short, fine cellulose fibres that are used in pulp for high-quality book and magazine paper.

The wide range of topics studied by using P. trichocarpa include the effects of ethylene, lignin biosynthesis, drought tolerance, and wood formation.

The Chehalis believed that the tree was intelligent and had a form of special physical agency, moving on its own without the need of wind.

[19] These results may be important in resolving debate in evolutionary biology regarding somatic mutation (that evolution can occur within individuals, not solely among populations), with a variety of implications.