Populus deltoides is a large
tree growing to tall and with a trunk up to diameter, one of the largest North American
hardwood trees. The
bark is silvery-white, smooth or lightly fissured when young, becoming dark gray and deeply fissured on old trees. of a mature tree The twigs are grayish-yellow and stout, with large triangular leaf scars. The winter buds are slender, pointed, long, yellowish brown, and resinous. It is one of the fastest growing trees in North America. In Mississippi River bottoms, height growth of per year for a few years has been seen. Sustained growth of in height and in diameter per year for 25 years is common. The
leaves are large, deltoid (triangular), long and broad with a truncated (flattened) base and a petiole long. The leaf is very coarsely toothed, the teeth are curved and gland tipped, and the petiole is flat; they are dark green in the summer and turn yellow in the fall (but many cottonwoods in dry locations drop their leaves early from the combination of drought and leaf rust, making their fall color dull or absent). Due to the flat stem of the leaf, the leaf has the tendency to shake from even the slightest breeze. This is one of the identifying characteristics. It is
dioecious, with the
flowers (
catkins) produced on single-sex trees in early spring. The male (pollen) catkins are reddish-purple and long; the female catkins are green, long at pollination, maturing long with several seed capsules (samaras) in early summer, which split open to release the numerous small
seeds attached to
cotton-like strands. A single tree may release 40 million seeds a season. == Variation ==