Populus angustifolia James
Species Image Gallery
(opens in a new window)
Family: Salicaceae
Genus: Populus
Species Synonyms: Populus balsamifera var. angustifolia (James) S. Wats.
Populus canadensis var. angustifolia (James) Wesmael
Populus fortissima A. Nels. & J.F. Macbr.
Populus salicifolia Raf.
Populus X sennii Boivin
Populus tweedyi Britt.
Common Names: narrowleaf cottonwood
Canada: southwestern Alberta – southwestern Saskatchewan
Saskatchewan: southwestern Saskatchewan; Cypress Hills
Ecoregion: Cypress Hills
Saskatchewan: small creek valleys
Canada: streambanks, plains, and foothills
Provincial Status According
to Harms (2003):
Nature Conservancy Status:
G5 S1
Saskatchewan Species at
Risk Status:
Populus angustifolia is endangered because it is extremely rare and regionally restricted in Saskatchewan. This species is almost always locally sparse. Immediate or probable threats have been identified.
Height: to 15 m
Stems: diameter at breast height (dbh) 20 – 50 cm; bark greenish to light brown, shallowly furrowed on lower portion of truck, smooth above; branches ascending, orangey to greenish-brown; branchlets glabrous; winter buds reddish, resinous, glabrous
Leaves: alternate, simple, petiole short and terete, blade 5 – 12 cm long, lanceolate to ovate, base cuneate to subcordate, apex acute to acuminate, dark green above, pale green below, margins finely crenate
Inflorescence: catkins appearing with the leaves, pendulous, 3 – 8 cm long, rachis slightly pubescent or glabrous; pedicels to 1.5 mm long
Flowers: actinomorphic; bracts membranous, lacerate or lobed, caducous; nectar-disc cup-shaped, 1 – 2 mm wide; in staminate flowers stamens 10 – 20, filaments free; in carpellate flowers ovary conic or ovoid, stigmas 2 – 4
Fruits: capsule subsessile, 3 – 7 mm long, narrowly ovate, rugose; seeds comose
1 Blades lanceolate to narrowly ovate, at least 1.5 times as long as wide
1 Blades ovate to deltoid, less than twice as long as wide
2 Leaf blades serrate in the middle of the leaf; stamens 25 – 40; blades green on both sides
P. x acuminata
2 Leaf blades serrate along the whole margin; stamens 10 – 25; blades lighter on the underside
3 Petioles less than 1 cm long, less than one-third the length of the blade
P. angustifolia
3 Petioles greater than 1 cm long, more than one-third the length of the blade
4 Leaves pale green to white, but not strongly glaucous beneath; base cuneate; first-year twigs orangey
P. x brayshawii
4 Leaves white and strongly glaucous beneath; base rounded; first-year twigs reddish
P. balsamifera ssp. balsamifera
5 Petiole strongly flattened; stamens 6 – 12; bark on trunk mostly smooth, usually white
P. tremuloides
5 Petiole terete or nearly so for most of their length or flattened; stamens 15 – 80; bark on trunk furrowed, usually grey
6 Blades of early leaves ovate, apex acute; winter buds very resinous and fragrant
P. balsamifera ssp. balsamifera
6 Blades of early leaves deltoid; apex acuminate; winter buds very or slightly resinous, not fragrant
7 Blades of early leaves dark green above, light green below; margin coarsely crenate-serrate, largest teeth 1 – 2 mm; petioles nearly round
P. x jackii
7 Blades of early leaves light green above and below; margin coarsely crenate-serrate or dentate, largest teeth 2 – 6 mm; petioles flattened at the junction with the blade
8 Pedicels 1 – 6 mm long; leaf base with 2 prominent basilaminar glands
P. deltoides ssp. monolifera
8 Pedicels longer than 6 mm; leaf base with 3 – 5 prominent basilaminar glands
P. deltoides ssp. deltoides