Identifying Features:
For
Poplars Cottonwoods & Apens:
-Alternate,
Simple Leaves
-Often triangular
-Long leafstalks, often flattened
-Bundle Scars are 3
-Seeds hairy or fluffy.
For
Black Cottonwood:
-Leafstalks
not flattened.
Images
(All
of these images come from the CalFlora Website)
This
image shows the fluffy seed heads characteristic of the Poplar
Family.
Photographer: Brother Alfred Brousseau
This photo gives a nice sense of the Black Cottonwood's overall shape
Photographer: Charles Webber
Another photo showing the fluffy seeds that give the cottonwoods their name. This one also shows a little of the leaf shape.
Photographer: Brother Alfred Brousseau
Where are Black Cottonwoods found?
Black Cottonwoods are native to the Pacific Coast from Alaska to Baja. They are also found inland to Alberta and the Rocky Mountain States.
They prefer rich, alluvial soil that is subjected to occasional flooding.
If you find a group of Black Cottonwoods, also look for:
Along
the Pacific Coast at low elevations:
Pacific Willow (Salix lasiandra)
Scouler Willow (S. scouleriana)
Northwest Willow (S. sessilifolia)
River Willow (S. fluviatilis)
In
higher elevation coastal forests:
Red Alder (Alnus rubra)
Bigleaf
Maple (Acer macrophyllum)
Oregon Ash (Fraxinus latifolia)
Douglas-fir (Pseudotsuga menziesii)
Western Redcedar (Thuja plicata)
Grand Fir (Abies grandis)
Inland:
Ponderosa Pine (Pinus ponderosa)
Western White Wine (P. monticola)
White Fir (Abies concolor)
Western Larch (Larix occidentalis)
Succession Status
Black Cottonwood is one of the first trees to come back to an area that has been recently disrupted by fire or other clearing process. It is fast growing and not very shade tolerant so it quickly outpaces other species. Eventually, it is replaced by trees that are more shade tolerant.
Ecological Use
Bald eagles, ospreys, and blue herons have been known to nest in Black Cottonwood crowns. Woodpeckers, great horned owls, wood ducks, flying squirrels, raccoons, and a variety of songbirds nest in black cottonwood trunk cavities. Beavers use black cottonwood for food and building materials. Because Black Cottonwoods are high water users, they can grow near streams where they help prevent streambed erosion. Fallen trunks are used by some animals for shelter, especially in areas where other large trees are scarce.
Black Cottonwood (Populus trichocarpa)
