Black cottonwood – Populus trichocarpa

Pronunciation: pop’-you-lus try-koh-kar-puh

Leaf: Alternate, simple, deciduous; variable in size and shape on same tree, commonly 3 - 6 inches long, but can be much larger; ovate-lanceolate to deltoid, dark green above and silvery white below with rusty smears of resin, margins wavy to crenate; petiole long, and most often round but may be flattened.

Flower: Species is dioecious; borne in long, drooping aments that appear before the leaves.

Fruit: Rounded, 3 - valved capsules (¼ to ½ inch in diameter) which open to release many cottony-tufted seeds; seeds are very tiny and black.

Twig: Moderately stout, greenish brown to olive-gray, often ribbed or angled in cross section when young, covered with distinct lenticels, spur shoots are common on older branches; buds are long (½ to ¾ inch) and sharp-pointed, resinous and aromatic, covered with imbricate scales. Twig has a bitter aspirin taste.

Bark: When young it is smooth and yellowish tan to gray; later gray to gray-brown and broken into deep furrows and flattened ridges, up to 2 ½ inches thick.

Form: The tallest broad-leaved tree in the West, growing to 200 feet tall and 6 feet in diameter. Has a broad, open crown.

Looks like: balsam poplar - quaking aspen - narrowleaf cottonwood - Fremont cottonwood

Populus balsamifera ssp. trichocarpa - black cottonwood Latin name / balsam bearing

https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/idpmcar6107.pdf