POPULUS is a genus of 25–35 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 /ˈpɒp.lər/ , ASPEN , and COTTONWOOD .
In the September 2006 issue of Science Magazine , the Joint Genome Institute announced that the western balsam poplar (P. trichocarpa ) was the first tree whose full DNA code had been determined by DNA sequencing .
* 1 Description * 2 Ecology
* 3 Classification
* 3.1 Selected species
* 4 Cultivation
* 4.1 India
* 5 Uses
* 5.1 Manufacturing * 5.2 Energy * 5.3 Art and literature * 5.4 Susceptible to termites * 5.5 Land management * 5.6 Agriculture
* 6 See also * 7 References
The genus has a large genetic diversity, and can grow from 15–50 m (49–164 ft) tall, with trunks up to 2.5 m (8 ft 2 in) in diameter. Male catkins of Populus × canadensis
The bark on young trees is smooth, white to greenish or dark grey,
and often has conspicuous lenticels ; on old trees, it remains smooth
in some species, but becomes rough and deeply fissured in others. The
shoots are stout, with (unlike in the related willows ) the terminal
bud present. The leaves are spirally arranged, and vary in shape from
triangular to circular or (rarely) lobed, and with a long petiole ; in
species in the sections
The flowers are mostly dioecious (rarely monoecious ) and appear in early spring before the leaves. They are borne in long, drooping, sessile or pedunculate catkins produced from buds formed in the axils of the leaves of the previous year. The flowers are each seated in a cup-shaped disk which is borne on the base of a scale which is itself attached to the rachis of the catkin. The scales are obovate, lobed, and fringed, membranous, hairy or smooth, and usually caducous. The male flowers are without calyx or corolla , and comprise a group of four to 60 stamens inserted on a disk; filaments are short and pale yellow; anthers are oblong, purple or red, introrse, and two-celled; the cells open longitudinally. The female flower also has no calyx or corolla, and comprises a single-celled ovary seated in a cup-shaped disk. The style is short, with two to four stigmata, variously lobed, and numerous ovules. Pollination is by wind, with the female catkins lengthening considerably between pollination and maturity. The fruit is a two- to four-valved dehiscent capsule , green to reddish-brown, mature in midsummer, containing numerous minute light brown seeds surrounded by tufts of long, soft, white hairs which aid wind dispersal.
Poplarsu of the cottonwood section are often wetlands or riparian trees. The aspens are among the most important boreal broadleaf trees.
Poplars and aspens are important food plants for the larvae of a
large number of
* POPULUS SECTION POPULUS – ASPENS AND WHITE POPLAR (circumpolar subarctic and cool temperate, and mountains farther south, white poplar warm temperate)
* Populus alba – white poplar (Southern Europe to central Asia)
* POPULUS SECTION AIGEIROS – BLACK POPLARS, SOME OF THE COTTONWOODS (North America, Europe, western Asia; temperate)
* POPULUS SECTION TACAMAHACA – BALSAM POPLARS (North America, Asia; cool temperate)
Populus angustifolia – willow-leaved poplar or narrowleaf
cottonwood (Central North America)
Populus balsamifera – Ontario balsam poplar (northern North
America) (= P. candicans, P. tacamahaca)
* POPULUS SECTION LEUCOIDES – NECKLACE POPLARS OR BIGLEAF POPLARS (Eastern North America, eastern Asia; warm temperate)
* POPULUS SECTION TURANGA – SUBTROPICAL POPLARS (Southwest Asia, east Africa; subtropical to tropical)
* POPULUS SECTION ABASO – MEXICAN POPLARS (Mexico; subtropical to tropical)
Many poplars are grown as ornamental trees , with numerous cultivars used. They have the advantage of growing to a very large size at a rapid pace. Almost all poplars take root readily from cuttings or where broken branches lie on the ground (they also often have remarkable suckering abilities, and can form huge colonies from a single original tree, such as the famous Pando forest made of thousands of Populus tremuloides clones).
Trees with fastigiate (erect, columnar) branching are particularly popular, and are widely grown across Europe and southwest Asia. However, like willows , poplars have very vigorous and invasive root systems stretching up to 40 m from the trees; planting close to houses or ceramic water pipes may result in damaged foundations and cracked walls and pipes due to their search for moisture.
A simple, reproducible, high-frequency micropropagation protocol in eastern cottonwood Populus deltoides has been reported by Yadav et al. 2009
In India, the poplar is grown commercially by farmers, mainly in the Punjab region. Common poplar varieties are:
* G48 (grown in the plains of Punjab, Haryana, UP) * w22 (grown in mountainous regions, e.g., Himachal Pradesh, Pathankot, Jammu)
The trees are grown from kalam or cuttings, harvested annually in January and February, and commercially available up to 15 November.
Most commonly used to make plywood , Yamuna Nagar in Haryana state has a large plywood industry reliant upon poplar. It is graded according to sizes known as "over" (over 24 inches (610 mm)), "under" (18–24 inches (460–610 mm)), and "sokta" (less than 18 inches (460 mm)).
Traditional Pamiris house
Although the wood from
Its flexibility and close grain make it suitable for a number of applications, similar to those for willow. The Greeks and Etruscans made shields of poplar, and Pliny also recommended poplar for this purpose. Poplar continued to be used for shield construction through the Middle Ages and was renowned for a durability similar to that of oak, but at a substantial reduction in weight.
* In many areas, fast-growing hybrid poplars are grown on plantations for pulpwood * Poplar is widely used for the manufacture of paper . * It is also sold as inexpensive hardwood timber , used for pallets and cheap plywood ; more specialised uses include matches and the boxes in which Camembert cheese is sold. * Poplar wood is also widely used in the snowboard industry for the snowboard core, because it has exceptional flexibility, and is sometimes used in the bodies of electric guitars and drums . * Poplar wood, particularly when seasoned, makes a good hearth for a bow drill . * Due to its high tannic acid content, the bark has been used in Europe for tanning leather. * Poplar wood can be used to produce chopsticks or wooden shoes . * Baking moulds from peeled poplar may be used in the freezer, oven, or microwave oven.
Interest exists in using poplar as an energy crop for biomass or biofuel , in energy forestry systems, particularly in light of its high energy-in to energy-out ratio, large carbon mitigation potential, and fast growth. Rotor poplar and willow cuttings planter, planting a new nursery of poplar for biomass with short rotation
ART AND LITERATURE
Poplar was the most common wood used in Italy for panel paintings ;
Some stringed instruments are made with one-piece poplar backs; violas made in this fashion are said to have a particularly resonant tone. Similarly, though typically it is considered to have a less attractive grain than the traditional sitka spruce , poplar is beginning to be targeted by some harp luthiers as a sustainable and even superior alternative for their sound boards : in these cases another hardwood veneer is sometimes applied to the resonant poplar base both for cosmetic reasons, and supposedly to fine-tune the acoustic properties.
The Odd Poplers Alley, in Iași , Romania, is one of the spots where Mihai Eminescu sought inspiration in his works (the poem "Down Where the Lonely Poplars Grow"). In 1973, the 15 white poplars still left (with age ranges between 233 and 371 years) were declared natural monuments.
SUSCEPTIBLE TO TERMITES
In Pakistan, poplar is grown on commercial level by farmers in Punjab, Sindh, and Khyber Pakhtunkhwa Provinces. However, all varieties are seriously susceptible to termite attack, causing significant losses to poplar every year. Logs of poplar are therefore also used as bait in termite traps (termaps) for biocontrol of termites in crops.
Lombardy poplars are frequently used as a windbreak around agricultural fields to protect against wind erosion.
Logs from the poplar provide a growing medium for shiitake mushrooms.
Wikimedia Commons has media related to POPULUS .
* ^ "Genus POPULUS (POPLARS)". Taxonomy. UniProt. Retrieved 4
* ^ Joint Genome Institute,
* v * t * e
Bow and arrow
* Crown of thorns
* Mason\'s mitre
Mortise and tenon
American Association of Woodturners
* Wd : Q25356 * EoL : 39565 * FloraBase : 22616 * FNA : 126537 * FOC : 126537 * Fossilworks : 55955 * GBIF : 3040183 * GRIN : 9759 * iNaturalist : 47566 * IPNI : 36051-1 * ITIS : 22444 * NCBI : 3689 * PLANTS : POPUL * Tropicos : 40014915 * VASCAN: 1583
* GND : 4173223-6 * NDL