View All Stallergenes Greer web sites
Back to previous screen

Black Cottonwood

TREES

GENUS/SPECIES


Populus trichocarpa

FAMILY


Salicaceae

SYNONYMS


Common: Western Balsam-Poplar
Botanical: Populus balsamifera ssp., trichocarpa

DISTRIBUTION


Western US

  • NW California northward to NW Washington
  • NW Washington Eastward to W Montana
  • W Montana southwestward to NW California
  • SE to south central Alaska
  • Outliers in central and S California, Nevada, N Utah, NW Wyoming, and SW North Dakota

Comments

There is some disagreement as to the western border of the range of this species because of the status and distinctness of the closely related balsam poplar, found mainly in the subarctic spruce forests. Rather large amounts of wind-borne pollen are released from male catkins in the spring. The name “cottonwood” refers to the fluffy down that is attached to the seeds, produced by female trees soon after pollination. This tree, which grows rapidly, is typically found on the floodplains of rivers and streams, but is capable of growing on higher ground. The resin has a pleasant odor. The blades of the leaves tend to be longer than wide, having somewhat of a pear shape. The wood is put to many uses and the tree is also planted for shade and windbreaks.