cottonwood

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several North American poplar trees, especially Populus deltoides, which has triangular leaves and a tuft of cottony hairs on the seeds.

Century Dictionary and Cyclopedia

1. n. The name of several species of the genus Populus the United States, from the light cottony tuft at the base of the numerous small seeds. The common eastern species are P. monilifera and the swamp- or river-cottonwood, P. heterophylla. West of the Rocky Mountains the cottonwoods are P. angustifolia, P. Fremontii, and P. trichocarpa. The wood is very light, soft, and close-grained, liable to warp and difficult to season, but largely used in the manufacture of paper-pulp, and for barrels, packing-cases. woodenware, etc. Cross-sections of the trunk of P. monilifera are used as polishing-wheels in glass-grinding.
2. n. In Australia, a tree of the aster family, Bedfordia salicina: so called from the cottony under-surface of the leaves, or its hard, brownish, mottled wood. Called dogwood and honeywood in Tasmania.

Wiktionary

1. n. A number of species of tree in the genus Populus (poplars), typically growing along watercourses.

GNU Webster's 1913

1. n. (Bot.) An American tree of the genus Populus or poplar, having the seeds covered with abundant cottonlike hairs; esp., the Populus monilifera and Populus angustifolia of the Western United States.

WordNet 3.0

1. n. any of several North American trees of the genus Populus having a tuft of cottony hairs on the seed
2. n. American basswood of the Allegheny region