Populus balsamifera subsp. trichocarpa L. (Torr. & A. Gray ex Hook.) Brayshaw
black cottonwood
Salicaceae (Willow family)

Introduction to Vascular Plants


© Bryan Kelly-McArthur     (Photo ID #81376)


E-Flora BC Static Map

Distribution of Populus balsamifera subsp. trichocarpa
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Species Information

Dioecious tree up to 50 m tall; not colonial; branches brown the first year, turning grey later; twigs smooth or sparsely hairy.
Alternate, deciduous, simple, narrowly to broadly egg-shaped or lanceolate, 5-20 cm long, 3-12 cm wide, the bases tapered to heart-shaped or squared-off smooth, finely toothed and hairy on the margins, the teeth often tipped with a callous gland, lower side whitish or pale green and brownish; leaf stalks 2-10 cm long, often with a pair of glands near the blade; buds finely hairy with fringed scales.
Borne in catkins; male catkins 2-3 (5) cm long, soon deciduous, with 8-60 stamens; female catkins 8-20 cm long.
Capsules, broadly egg-shaped, carpels 2-3, smooth or hairy, nearly unstalked.
Two subspecies occur in BC. The hybrids P. angustifolia James x P. balsamifera ssp. trichocarpa (P. x brayshawii Boivin) and P. balsamifera ssp. trichocarpa x P. nigra L. var. italica DuRoi are rare in BC .

1. Ovaries and capsules smooth; leaves pale green and brownish beneath.................... ssp. balsamifera

1. Ovaries and young capsules hairy; leaves whitish beneath.................... ssp. trichocarpa (T. & G.) Brayshaw

SourceThe Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: White
Present over the Spring
Source:  The USDA

Habitat and Range

Moist uplands and floodplains in the montane zone; ssp. balsamifera - common in N and E BC; ssp. trichocarpa - common throughout BC except rare on Queen Charlotte Islands; ssp. balsamifera - N to YT, AK and NT, E to NF and S to NY, VA, IL, IA, CO, ID and OR; ssp. trichocarpa - N to S AK and YT, E to SW AB and S to ND, WY, UT, NV and CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Populus balsamifera var. californica S. Wats.
Populus hastata Dode p.p.
Populus trichocarpa Torr. & A. Gray ex Hook.
Populus trichocarpa subsp. hastata (Dode) Dode p.p.
Populus trichocarpa var. cupulata S. Watson
Populus trichocarpa var. hastata (Dode) A. Henry p.p.
Populus trichocarpa var. ingrata (Jeps.) Jeps.