| Populus sect. Populus | |
|---|---|
| |
| Leaves of Populus alba, the type species of the section | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Salicaceae |
| Genus: | Populus |
| Section: | Populus sect. Populus |
| Species | |
|
See text | |
| Synonyms[1] | |
| |
Populus section Populus, of the Populus (poplar) genus, includes the aspen trees and the white poplar Populus alba.[2] The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by contrast, is native to warmer regions, with hot, dry summers.[citation needed] These trees are all medium-sized deciduous trees ranging 15–30 metres (49–98 ft) tall.
All of the species in section Populus typically grow in large clonal colonies derived from a single seedling, and spreading by means of root suckers; new stems in the colony may appear at up to 30–40 metres from the previous trees. Each individual tree can live for 40–150 years above ground, but the root system of the colony is long-lived, sending up new trunks as the older trunks die off above ground, spreading about a metre per year, sometimes eventually covering many hectares. They are able to survive forest fires because the roots are below the heat of the fire, and new sprouts can grow from the roots. One colony of American aspen (P. tremuloides) in Utah, given the nickname of "Pando", has been estimated to be 80,000 years old (disputed), making it possibly the oldest living colony of aspens.
- ^ "Tropicos.org". Missouri Botanical Garden. Retrieved 25 February 2012.
- ^ "technology transfer fact sheet: Populus spp" (PDF). Forest Products Laboratory: R&D USDA. Madison, Wisconsin: United States Department of Agriculture Forest Service. Retrieved 20 September 2010.