The Cottonwood is considered by Dr. Gray* to be the monilifera of Aiton, and the laevigata of Will-denow. Wood's No. 5 monilifera of Aiton. seems to be different with habitat"on the Hudson, near Troy, N. Y., apparently native".

"Fide Beck."t Michaux found this species as far northward as 43°. It is abundant in the Black Swamp. in northwestern Ohio, and fine trees may be seen on the banks of the river below Detroit,. Mich. Michaux describes the tree as larger than the angulata, and the bark as thicker and more deeply furrowed, having a wider head and with the boughs more thickly branched. This character of the outer bark has attracted the attention of the fishermen on the banks, who utilize it as a substitute for the more costly bark Quercus suber, or cork. Sections of this substance, often three inches thick, are turned into oval form and perforated, so as to be used as-floats to their gill-nets.

Michaux reports this species rare on the Atlantic slope, but very common on the Mississippi above the Arkansas. At the mouth of the last named river it grows abundantly around the town of Napoleon. It is the chief source of the steamboat fuel on our southern streams.