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| Eastern Cottonwood | ||||||||||||||||
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 Eastern Cottonwood
Populus deltoides |
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| Populus deltoides W.Bartram ex Marshall |
The Eastern Cottonwood (Populus deltoides) is a cottonwood poplar native to North America, growing throughout the eastern, central, and southwestern United States, the southernmost part of eastern Canada, and northeastern Mexico.[1]
It is a large tree growing to 20–40 m tall and with a trunk up to 1.8 m 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. The twigs are grayish-yellow, stout, with large triangular leaf scars. The winter buds are slender, pointed, 1–2 cm long, yellowish brown, and resinous. The leaves are large, deltoid (triangular), 4–10 cm long and 4–11 cm broad with a truncated (flattened) base and a 3–12 cm long, flat petiole; they are dark green in the summer and turn yellow in the fall. It is dioecious, with the flowers (catkins) produced on single-sex trees in early spring. The male (pollen) catkins are reddish-purple, 8–10 cm long; the female catkins are green, 7–13 cm long at pollination, maturing 15–20 cm long with several 6–15 mm seed capsules in early summer, which split open to release the numerous small seeds attached to cotton-like strands.[2][3][4]
There are three subspecies:[1]
- Populus deltoides subsp. deltoides. Eastern Cottonwood. Southeastern Canada (the south of Ontario and Quebec), eastern United States (throughout, west to North Dakota to Texas).
- Populus deltoides subsp. monilifera (Aiton) Eckenw. Plains Cottonwood (syn. P. deltoides var. occidentalis Rydb.; P. sargentii Dode). South central Canada, in the south of Alberta, Saskatchewan, and Manitoba, and central United States south to northern New Mexico and Texas.
- Populus deltoides subsp. wislizeni (S.Watson) Eckenw. Rio Grande Cottonwood (syn. P. wislizeni (S.Watson) Sarg.; P. fremontii var. wislizeni S.Watson). Southern Colorado south through Texas to northeastern Mexico (Chihuahua, San Luis Potosi), and west to Arizona (presence in California, listed by GRIN[1], is doubtful, not included in the Jepson Flora of California[5]).
Ecology
It needs bare soil and full sun for successful germination and establishment; in natural conditions, it usually grows near rivers, with mud banks left after floods providing ideal conditions for seedling germination; human soil cultivation has allowed it to increase its range away from such habitats.[4]
The leaves serve as food for caterpillars of various Lepidoptera. See List of Lepidoptera that feed on poplars.
References
- ^ a b c Germplasm Resources Information Network: Populus deltoides
- ^ USGS Aquatic and Wetland Vascular Plants of the Northern Great Plains: Populus deltoides
- ^ v-Plants (Chicago Herbarium): Populus deltoides
- ^ a b US Forest Service Silvics Manual: Populus deltoides
- ^ Jepson Flora: Populus; clicking 'next taxon' through the genus shows no entry for this taxon)
