Page authors: Don Knoke, David Giblin
Populus trichocarpa
black cottonwood

Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to Alberta and Wyoming.

Habitat: Streambanks, riparian zones, river corridors, and moist woods, from sea level to middle elevations in the mountains.

Flowers: April-June

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Rough-barked, dioecious tree up to 50 m. tall; buds large, the scales very resinous, glabrous.


Leaves alternate, the blades fragrant, strongly resinous, the lower side distinctly paler than the upper, variable in shape, 5-15 cm. long and 3-9 cm. wide, broadest below the middle, pointed at the tip and usually rounded or truncate at the base, the surfaces usually glabrous; petioles terete, about half as long as the blade.


Catkins drooping; the bracts subtending the flowers in the catkins lacerate-fringed; staminate catkins elongating to 2-3 cm, then deciduous; pistillate catkins at maturity 8-20 cm. long; stigmas 2, broadly dilated.


Capsules rotund-ovate, 5-8 mm. long, sub-sessile.

Accepted Name:
Populus trichocarpa Torr. & A. Gray
Publication: Icon. Pl. 9: plate 878. 1852.

Synonyms & Misapplications:
Populus balsamifera L., misapplied [FNA7, HC2]
Populus balsamifera L. ssp. trichocarpa (Torr. & A. Gray) Brayshaw [JPM, KZ99]
Populus balsamifera L. var. californica S. Watson
Populus trichocarpa Torr. & A. Gray ex Hook. var. cupulata S. Watson
Populus trichocarpa Torr. & A. Gray var. ingrata (Jeps.) Parish
Additional Resources:

PNW Herbaria: Specimen records of Populus trichocarpa in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Populus trichocarpa checklist entry

OregonFlora: Populus trichocarpa information

E-Flora BC: Populus trichocarpa atlas page

CalPhotos: Populus trichocarpa photos

98 photographs:
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