Open English Wordnet
Nouns
(n)swamp cottonwood, black cottonwood, downy poplar, swamp poplar, Populus heterophyllaNorth American poplar with large rounded scalloped leaves and brownish bark and wood
(n)black cottonwood, Western balsam poplar, Populus trichocarpacottonwood of western North America with dark green leaves shining above and rusty or silvery beneath