Populus is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar, aspen, and cottonwood.
Populus section Populus, of the Populus (poplar) genus, includes the aspen trees and the white poplar Populus alba. 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. These trees are all medium-sized deciduous trees ranging 15–30 metres (49–98 ft) tall.
Populus tremuloides is a deciduous tree native to cooler areas of North America, one of several species referred to by the common name aspen. It is commonly called quaking aspen, trembling aspen, American aspen, mountain or golden aspen, trembling poplar, white poplar, and popple, as well as others. The trees have tall trunks, up to 25 metres tall, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden to yellow, rarely red, in autumn. The species often propagates through its roots to form large clonal groves originating from a shared root system. These roots are not rhizomes, as new growth develops from adventitious buds on the parent root system.
Trembling aspen is the popular name for either:
The poplar admiral is a butterfly in the Limenitidine clade of the family Nymphalidae.
Populus tremula is a species of poplar native to cool temperate regions of the Old World.
Laspeyria flexula, the beautiful hook-tip, is a moth of the family Erebidae. The species was first described by Michael Denis and Ignaz Schiffermüller in 1775. It is found in the Palearctic realm.
Archiearis notha, the light orange underwing, is a moth of the family Geometridae. The species was first described by Jacob Hübner in 1803 and can be found in Europe.
Stigmella assimilella is a moth of the family Nepticulidae. It is found in most of Europe, east through Russia to the eastern part of the Palearctic realm.
Ectoedemia argyropeza is a moth of the family Nepticulidae. It is a widespread species, with a Holarctic distribution.
Phyllonorycter apparella, the aspen leaf blotch miner moth, is a moth of the family Gracillariidae. It is found in most of Europe. It is also present in Turkey and North America.
Notodonta tritophus, the three-humped prominent, is a moth of the family Notodontidae. The species was first described by Michael Denis and Ignaz Schiffermüller in 1775. It is found in most of Europe, east to the Caucasus and Armenia.
Rheumaptera undulata, the scallop shell, is a moth of the family Geometridae. It was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. It is found in most of the Palearctic realm and North America.
Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section Populus, of the Populus genus.
Stegania cararia, the ringed border, is a species of moth of the family Geometridae. It is found from France east to Russia. It is an immigrant in Great Britain. The habitat consists of damp forested areas.
Populus × canescens, the grey poplar, is a hybrid between Populus alba and P. tremula. It is intermediate between its parents, with a thin grey downy coating on the leaves, which are much less deeply lobed than the leaves of P. alba. It is a very vigorous tree with marked hybrid vigour, reaching 40 metres tall and with a trunk diameter over 1.5 m (5 ft) – much larger than either of its parents. Most trees in cultivation are male, but female trees occur naturally and some of these are also propagated.
Aspen trunk rot is a fungal disease that causes stem decay heart rot of living aspen trees. The pathogen that causes this disease is the fungus Phellinus tremulae. Most of the symptoms of this disease are internal, with the only external signs of a diseased aspen being fruiting bodies called conks. A single conk found on an aspen can indicate advanced decay of up 82% of the tree volume. Internal decayed wood of freshly cut aspens is spongy, yellow/white colored, surrounded by black zones of discoloration, and contains a distinct wintergreen smell. The fungus is spread via airborne spores released from the fruiting body which can infect through dead branches, branch stubs, or wounds in the tree. Although no direct management control is known, harvesting aspen stands that have been damaged or harvesting stands before decay becomes advanced minimizes tree loss. Aspen wood is white, malleable but strong, and heat-tolerant and therefore has many commercial uses including matches, packing paper, lumber, plywood, pulp, and animal beds. Aspen trees diseased with aspen trunk rot decrease the economic value of the lumber.
In Finland, Kotiranta and Niemelä introduced a widely used method for comparing the conservation values of different forest areas, based on the observation that certain wood-rotting fungi are very sensitive to the impact of human activities on forest ecosystems. Such species are slow to return to areas from where they have disappeared, so their presence is evidence of a long continuity in forest ecosystems.
Agrilus suvorovi is a species of beetle in the family Buprestidae, the jewel beetles.
Harmandiola tremulae, the aspen leaf gall midge, is a species of gall midges in the family Cecidomyiidae.
