Cottonwood

:This article is about the poplar plant. For other uses of the term, see Cottonwood (disambiguation).

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Populus deltoides L.

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Populus fremontii

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Populus nigra L.

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The cottonwoods are three species of poplars in the section Aegiros of the genus Populus, native to North America, Europe and western Asia.

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The name is also commonly used for any species of poplar in the United States, including some poplars not in the section Aegiros, notably the Swamp cottonwood Populus heterophylla (in the section Leucoides) and the Black and Narrowleaf Cottonwoods P. trichocarpa and P. angustifolia (balsam poplars in the section Tacamahaca).

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Those in section Aegiros are large deciduous trees 20-45 m tall, distinguished by thick, deeply fissured bark, and triangular-based to diamond-shaped leaves, green on both sides (without the whitish wax on the undersides of balsam poplar leaves), and without any obvious balsam scent in spring. An important feature of the leaves is the petiole which is flattened sideways, so that the leaves have a particular type of movement in the wind. The aspens (Populus section Populus) share this characteristic, but not the balsam poplars.

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Male and female flowers are in separate catkins, appearing before the leaves in spring. The seeds are borne on cottony structures which allow them to be blown long distances in the air before settling to ground.

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The cottonwoods are exceptionally tolerant of flooding, erosion and flood deposits filling around the trunk.

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In the past up to five or six species were accepted, but recent trends have been to accept just three species, treating the others as subspecies of P. deltoides.

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The Eastern Cottonwood Populus deltoides is one of the largest North American hardwood trees, although the wood is rather soft. It is a riparian zone tree. It occurs throughout the eastern United States and just into southernmost Canada. The leaves are alternate and simple, with coarsely-toothed (crenate/serrate) edges, and subcordate at the base. The leaf shape is roughly triangular, hence the species name, deltoides.

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In the typical subspecies deltoides (Vermont south to northern Florida and west to about Michigan), the leaves are broad triangular, 7-15 cm across at the base. Further west (Minnesota south to eastern Texas), the subspecies molinifera (Plains Cottonwood; syn. P. sargentii) has somewhat narrower leaves 5-10 cm wide at the base. This is also the state tree of Wyoming. In western Texas, New Mexico and Colorado the subspecies wislizeni (Rio Grande Cottonwood; syn. P. wislizeni) occurs.

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The Fremont Cottonwood Populus fremontii occurs in California east to Utah and Arizona and south into northwest Mexico; it is similar to Eastern Cottonwood, differing mainly in the leaves having fewer, larger serrations on the edge, and small differences in the flower and seed pod structure.

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The third species, Black Poplar Populus nigra, native of Europe and western Asia, is distinct in its much smaller leaves, 5-11 cm across, with a more rhombic (diamond) shape; see the link for further details.

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Poplar: This article is about woody plants of the genus Populus....

North America: North America is a continent in the northern hemisphere, bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the North Pacific Ocean. It covers an area of 9,355,000 square miles (24,230,000 square kilometers). In 2...

Europe: :This article is about the continent. For other meanings, see Europe (disambiguation)....

Cottonwood related Images and Photos (experimental)

Cottonwood Brave	Silhouette of a Cotton Wood Tree at Sunrise Lake Erie Michigan USA	Cottonwood Country I	Fremont Cottonwood Leaf and Seeds in the Spring (Populus Fremontii) Utah USA
Black Cottonwood Tree in Fall Colors Populus Trichocarpa Western North America	Loggerhead Shrike at Cottonwood Springs Joshua Tree National Park California