Populus
Populus Temporal range:
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Leaf of Populus tremula | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Malpighiales |
Family: | Salicaceae |
Subfamily: | Salicoideae
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Tribe: | Saliceae |
Genus: | Populus L. |
Type species | |
Populus tremula L.
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Sections and species | |
See text |
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 (/ˈpɒplər/), aspen, and cottonwood.
The western balsam poplar (P. trichocarpa) was the first tree to have its full DNA code determined by DNA sequencing, in 2006.[1]
Description
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) in diameter.
The
The
Classification
The genus Populus has traditionally been divided into six sections on the basis of leaf and flower characters;[3][5] this classification is followed below. Recent genetic studies have largely supported this, confirming some previously suspected reticulate evolution due to past hybridisation and introgression events between the groups. Some species (noted below) had differing relationships indicated by their nuclear DNA (paternally inherited) and chloroplast DNA sequences (maternally inherited), a clear indication of likely hybrid origin.[6] Hybridisation continues to be common in the genus, with several hybrids between species in different sections known.[2][7] There are currently 57 accepted species in the genus.[8]
Phylogeny
Some of the most easily identifiable fossils of this genus belongs to Poplus wilmattae, which come from the Late Paleocene of North America about 58 million years ago.[9] However, fossils from the Cretaceous of this genus have been found in Tibet and Heilongjiang, China.[10]
Selected species
- Populus section Populus – aspens and white poplar (circumpolar subarctic and cool temperate, and mountains farther south, white poplar warm temperate)
- Populus adenopoda – Chinese aspen (eastern Asia)
- Populus alba – white poplar (southern Europe to central Asia)
- Populus × canescens (P. alba × P. tremula) – grey poplar
- Populus davidiana – Korean aspen (eastern Asia)
- Populus grandidentata – bigtooth aspen (eastern North America)
- Populus luziarum – Jalisco, Mexico[11]
- Populus primaveralepensis – Jalisco, Mexico[11]
- Populus sieboldii – Japanese aspen (eastern Asia)
- Populus tremula – aspen, common aspen, Eurasian aspen, European aspen, quaking aspen (Europe, northern Asia)
- Populus tremuloides – quaking aspen or trembling aspen (North America)
- Populus section Aigeiros – black poplars, some of the cottonwoods (North America, Europe, western Asia; temperate)
- Populus deltoides – eastern cottonwood (eastern North America)
- Populus fremontii – Fremont cottonwood (western North America)
- Populus nigra – black poplar (Europe), placed here by nuclear DNA; cpDNA places it in sect. Populus (including Populus afghanica)
- Populus × canadensis (P. deltoides × P. nigra) – hybrid black poplar
- Populus × inopina (P. nigra × P. fremontii) – hybrid black poplar
- Populus section Tacamahaca – balsam poplars (North America, Asia; cool temperate)
- Populus angustifolia – willow-leaved poplar or narrowleaf cottonwood (central North America)
- Populus balsamifera – Balsam poplar (northern North America) (= P. candicans, P. tacamahaca)
- Populus cathayana – (northeast Asia)
- Populus ciliata – (Asia)
- Populus koreanaJ.Rehnder – Korean poplar (northeast Asia)
- Populus laurifolia – laurel-leaf poplar (central Asia)
- Populus maximowicziiA.Henry – Maximowicz' poplar, Korean poplar, Mongolian poplar, Japanese poplar (northeast Asia)
- Populus simonii – Simon's poplar (northeast Asia)
- Populus suaveolens Fischer – Korean poplar, Mongolian poplar, Japanese poplar (northeast Asia)
- Populus szechuanica – Sichuan poplar (northeast Asia), placed here by nuclear DNA; cpDNA places it in sect. Aigeiros
- Populus trichocarpa – western balsam poplar or black cottonwood (western North America)
- Populus tristis (northeast Asia), placed here by nuclear DNA; cpDNA places it in sect. Aigeiros
- Populus ussuriensis– Ussuri poplar (northeast Asia)
- Populus yunnanensis – Yunnan poplar (east Asia)
- Populus section Leucoides – necklace poplars or bigleaf poplars (eastern North America, eastern Asia; warm temperate)
- Populus heterophylla – downy poplar (southeastern North America)
- Populus lasiocarpa – Chinese necklace poplar (eastern Asia)
- Populus wilsonii – Wilson's poplar (eastern Asia)
- Populus section Turanga – subtropical poplars (southwest Asia, east Africa; subtropical to tropical)
- Populus euphratica – Euphrates poplar (North Africa, southwest and central Asia)
- Populus ilicifolia – Tana River poplar (East Africa)
- Populus section Abaso – Mexican poplars (Mexico; subtropical to tropical)
- Populus guzmanantlensis (Mexico) (may be conspecific with Populus simaroa)
- Populus mexicana – Mexico poplar (Mexico)
- Intersectional hybrids
- Populus × acuminata (P. angustifolia × P. deltoides) – lanceleaf cottonwood
- Populus Pacific albus[12] (North America)
Ecology
Poplars of the cottonwood section are often wetlands or
Poplars and aspens are important food plants for the larvae of a large number of Lepidoptera species. Pleurotus populinus, the aspen oyster mushroom, is found exclusively on dead wood of Populus trees in North America.
Several species of Populus in the United Kingdom and other parts of Europe have experienced heavy dieback; this is thought in part to be due to Sesia apiformis which bores into the trunk of the tree during its larval stage.[13]
Cultivation
Many poplars are grown as
Trees with
A simple, reproducible, high-frequency micropropagation protocol in eastern cottonwood Populus deltoides has been reported by Yadav et al. 2009.[14]
India
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.
Poplars are most commonly used to make
Uses
Although the wood from Populus is known as poplar wood, a common high-quality hardwood "poplar" with a greenish colour is actually from an unrelated genus Liriodendron. Populus wood is a lighter, more porous material.
Its flexibility and close grain make it suitable for a number of applications, similar to those of willow. The Greeks and Etruscans made shields of poplar, and Pliny the Elder also recommended poplar for this purpose.[15] Poplar continued to be used for shield construction through the Middle Ages and was renowned for a durability similar to that of oak, but with a substantial reduction in weight.
Food
In addition to the foliage and other parts of Populus species being consumed by animals, the starchy sap layer (underneath the outer bark) is edible to humans, both raw and cooked.[16]
Manufacturing
- In many areas, fast-growing hybrid poplars are grown on plantations for pulpwood
- Poplar is widely used for the manufacture of paper.[17]
- It is also sold as inexpensive hardwood Camembert cheese.
- 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.[4]
- Poplar wood can be used to produce wooden shoes.
- Baking moulds from peeled poplar may be used in the freezer, oven, or microwave oven.[18]
In Pakistan, poplar is grown on a 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 for biocontrol of termites in crops.
Energy
Interest exists in using poplar as an energy crop for biomass, in energy forestry systems, particularly in light of its high energy-in to energy-out ratio, large carbon mitigation potential, and fast growth.
In the United Kingdom, poplar (as with fellow energy crop willow) is typically grown in a short rotation coppice system for two to five years (with single or multiple stems), then harvested and burned - the yield of some varieties can be as high as 12 oven-dry tonnes per hectare every year.[19] In warmer regions like Italy this crop can produce up to 13.8, 16.4 oven-dry tonnes of biomass per hectare every year for biannual and triennial cutting cycles also showing a positive energy balance and a high energy efficiency.[20]
Fuel
Biofuel is another option for using poplar as bioenergy supply. In the United States, scientists studied converting short rotation coppice poplar into sugars for biofuel (e.g. ethanol) production.[21] Considering the relative cheap price, the process of making biofuel from SRC can be economically feasible, although the conversion yield from short rotation coppice (as juvenile crops) were lower than regular mature wood. Besides biochemical conversion, thermochemical conversion (e.g. fast pyrolysis) was also studied for making biofuel from short rotation coppice poplar and was found to have higher energy recovery than that from bioconversion.[22]
Art
Poplar was the most common wood used in Italy for panel paintings; the Mona Lisa and most famous early Italian Renaissance paintings are on poplar.[citation needed] The wood is generally white, often with a slightly yellowish colour.
Some
Land management
Agriculture
Logs from the poplar provide a growing medium for shiitake mushrooms.[24]
Phytoremediation
Poplar represents a suitable candidate for
Culture
Two notable poems in English lament the cutting down of poplars, William Cowper's "The Poplar Field" and Gerard Manley Hopkins' "Binsey Poplars felled 1879".
In Billie Holiday's "Strange Fruit", she sings "Black bodies swinging in the southern breeze/Strange fruit hanging from the poplar trees…".
The Odd Poplars 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.[32]
In Ukraine, one of neighborhoods of Kyiv is named after Populus nigra as Osokorky, a local name.
References
- ^ Joint Genome Institute, Populus trichocarpa Archived 2 May 2008 at the Wayback Machine
- ^ ISBN 0-901158-07-0.
- ^ ISBN 0-00-220013-9.
- ^ a b Keeler, H. L. (1900). Our Native Trees and How to Identify Them. New York: Charles Scribner's Sons. pp. 410–412.
- ISBN 9780660165066.
- ^ Hamzeh, M., & Dayanandan, S. (2004). Phylogeny of Populus (Salicaceae) based on nucleotide sequences of chloroplast TRNT-TRNF region and nuclear rDNA. Amer. J. Bot. 91: 1398-1408. Available online Archived 29 January 2008 at the Wayback Machine
- ISBN 978-0-660-18145-5.
- ^ "Populus L.". Plants of the World Online, Kew Science. Accessed 8 September 2021. [1] Archived 26 February 2023 at the Wayback Machine
- ISBN 978-92-5-107185-4. Archived(PDF) from the original on 8 August 2016. Retrieved 24 March 2020.
- PMID 36618663.
- ^ a b <Vázquez-García, José & Muñiz-Castro, Miguel Angel & González, Rosa & Nieves-Hernández, Gregorio & Pulido, Maria & Hernández-Vera, Gerardo & Delgadillo, Osvaldo. (2019). "Populus primaveralepensis sp. nov. (Salicaceae, Malpighiales), a new species of white poplar from the Bosque La Primavera Biosphere Reserve in Western Mexico". European Journal of Taxonomy. 2019. 10.5852/ejt.2019.498.
- ^ "A Forest in the Desert: Hybrid Poplar Plantation Feeds New Mill" (PDF). Archived (PDF) from the original on 29 November 2020. Retrieved 3 October 2019.
- ^ Martin-Garcia, J. "Patterns and monitoring of Sesia apiformis infestations in poplar plantations at different spatial scales". Journal of Applied Entomology.
- S2CID 42796629.
- ISBN 978-1-139-82699-0. Archivedfrom the original on 17 July 2023. Retrieved 22 November 2015.
- OCLC 799792.
- ^ Poplar cultivation in Europe Archived 3 November 2007 at the Wayback Machine
- ^ Aiken, Laura (18 April 2012). "Baking Bread Abroad". Bakers Journal. Archived from the original on 8 August 2016. Retrieved 11 June 2016.
- S2CID 35494995.
- S2CID 86414864.
- PMID 28592993.
- .
- ^ "Harps by Wm. Rees - WM REES HARP MYTH 8". Archived from the original on 26 March 2012. Retrieved 1 July 2011. Rees Harps Website, "Harp Myth #8".
- ^ Shiitake growth studies performed by RMIT Archived 3 January 2010 at the Wayback Machine
- ISSN 0013-936X.
- S2CID 3892759.
- ^ Werther Guidi Nissim, Alessandra Cincinelli, Tania Martellini, Laura Alvisi, Emily Palm, Stefano Mancuso, Elisa Azzarello, Phytoremediation of sewage sludge contaminated by trace elements and organic compounds, Environmental Research, Volume 164, July 2018, Pages 356-366, ISSN 0013-9351, https://doi.org/10.1016/j.envres.2018.03.009., landfill leachate
- PMID 20211551.
- ^ Meggo RE, Schnoor JL. Cleaning Polychlorinated Biphenyl (PCB) Contaminated Garden Soil by Phytoremediation. Environmental sciences. 2013;1(1):33-52
- PMID 9703485.
- PMID 16151227.
- ^ "Iași - the county of centuries-old trees". Agerpres.ro. 17 October 2017. Archived from the original on 6 August 2019. Retrieved 15 October 2018.
- Media related to Populus at Wikimedia Commons