Populus
| Populus Temporal range:
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|---|---|
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| Leaf ofPopulus tremula | |
Scientific classification
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Salicaceae |
| Subfamily: | Salicoideae |
| Tribe: | Saliceae |
| Genus: | Populus L. |
| Type species | |
| Populus tremula L.
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| Sectionsandspecies | |
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Seetext | |
Populusis a genus of 25–30 species ofdeciduousflowering plantsin the familySalicaceae,native to most of theNorthern Hemisphere.English names variously applied to different species includepoplar(/ˈpɒplər/),aspen,andcottonwood.
The western balsam poplar (P. trichocarpa) was the first tree to have its full DNA code determined byDNA sequencing,in 2006.[1]
Description
[edit]
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.
Thebarkon young trees is smooth and white to greenish or dark gray, and often has conspicuouslenticels;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 relatedwillows) the terminal bud present. Theleavesare spirally arranged, and vary in shape from triangular to circular or (rarely) lobed, and with a longpetiole;in species in the sectionsPopulusandAigeiros,the petioles are laterally flattened, so that breezes easily cause the leaves to wobble back and forth, giving the whole tree a "twinkling" appearance in a breeze. Leaf size is very variable even on a single tree, typically with small leaves on side shoots, and very large leaves on strong-growing lead shoots. The leaves often turn bright gold to yellow before they fall during autumn.[2][3]
Theflowersare mostlydioecious(rarelymonoecious) and appear in early spring before the leaves. They are borne in long, drooping, sessile or pedunculatecatkinsproduced from buds formed in the axils of the leaves from 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 withoutcalyxorcorolla,and comprise a group of four to 60stamensinserted on a disk; filaments are short and pale yellow;anthersare 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. Thefruitis a two- to four-valveddehiscentcapsule,green to reddish-brown, mature in midsummer, containing numerous minute, light-brownseedssurrounded by tufts of long, soft, white hairs aiding wind dispersal.[2][4]
Classification
[edit]
The genusPopulushas 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 pasthybridisationand introgression events between the groups. Some species (noted below) had differing relationships indicated by theirnuclear DNA(paternally inherited) andchloroplast DNAsequences (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
[edit]Some of the most easily identifiable fossils of this genus belongs toPoplus wilmattae,which come from theLate Paleoceneof 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
[edit]
- PopulussectionPopulus–aspensand 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)
- PopulussectionAigeiros– 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;cpDNAplaces it in sect.Populus(includingPopulus afghanica)
- Populus×canadensis(P. deltoides×P. nigra) – hybrid black poplar
- Populus×inopina(P. nigra×P. fremontii) – hybrid black poplar
- PopulussectionTacamahaca– 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 suaveolensFischer– Korean poplar, Mongolian poplar, Japanese poplar (northeast Asia)
- Populus szechuanica– Sichuan poplar (northeast Asia), placed here by nuclear DNA;cpDNAplaces it in sect.Aigeiros
- Populus trichocarpa– western balsam poplar or black cottonwood (western North America)
- Populus tristis(northeast Asia), placed here by nuclear DNA;cpDNAplaces it in sect.Aigeiros
- Populus ussuriensis– Ussuri poplar (northeast Asia)
- Populus yunnanensis– Yunnan poplar (east Asia)
- PopulussectionLeucoides– 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)
- PopulussectionTuranga– 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)
- PopulussectionAbaso– Mexican poplars(Mexico; subtropical to tropical)
- Populus guzmanantlensis(Mexico) (may be conspecific withPopulus simaroa)
- Populus mexicana– Mexico poplar (Mexico)
- Intersectional hybrids
- Populus × acuminata(P. angustifolia × P. deltoides) – lanceleaf cottonwood
- PopulusPacific albus[12](North America)
Ecology
[edit]Poplars of the cottonwood section are often wetlands orripariantrees. The aspens are among the most importantborealbroadleaf trees.[2]
Poplars and aspens are important food plants for thelarvaeof a large number ofLepidopteraspecies.Pleurotus populinus,the aspen oyster mushroom, is found exclusively on dead wood ofPopulustrees in North America.
Several species ofPopulusin the United Kingdom and other parts of Europe have experienced heavydieback;this is thought in part to be due toSesia apiformiswhich bores into the trunk of the tree during its larval stage.[13]
Cultivation
[edit]
Many poplars are grown asornamental trees,with numerouscultivarsused. 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 famousPandoforest made of thousands ofPopulus tremuloidesclones).
Trees withfastigiate(erect, columnar) branching are particularly popular, and are widely grown across Europe and southwest Asia. However, likewillows,poplars have very vigorous and invasive root systems stretching up to 40 metres (130 ft) 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 cottonwoodPopulus deltoideshas been reported by Yadav et al. 2009.[14]
India
[edit]
In India, the poplar is grown commercially by farmers, mainly in thePunjabregion. 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 fromkalamor cuttings, harvested annually in January and February, and commercially available up to 15November.
Poplars are most commonly used to makeplywood:Yamuna NagarinHaryanastate 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)).
Uses
[edit]
Although the wood fromPopulusis known as poplar wood, a common high-quality hardwood "poplar" with a greenish colour is actually from an unrelated genusLiriodendron.Populuswood 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, andPliny the Elderalso 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
[edit]In addition to the foliage and other parts ofPopulusspecies being consumed by animals, the starchy sap layer (underneath the outer bark) is edible to humans, both raw and cooked.[16]
Manufacturing
[edit]- In many areas, fast-growinghybridpoplars are grown onplantationsforpulpwood
- Poplar is widely used for the manufacture ofpaper.[17]
- It is also sold as inexpensive hardwoodtimber,used forpalletsand cheapplywood;more specialised uses including matches andmatchboxesand the boxes forCamembert cheese.
- Poplar wood is also widely used in thesnowboardindustry for the snowboard core, because it has exceptional flexibility, and is sometimes used in the bodies ofelectric guitarsanddrums.
- Poplar wood, particularly when seasoned, makes a good hearth for abow drill.
- Due to its hightannic acidcontent, the bark has been used in Europe for tanning leather.[4]
- Poplar wood can be used to producechopsticksorwooden shoes.
- Bakingmouldsfrompeeledpoplar 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
[edit]Interest exists in using poplar as anenergy cropforbiomass,inenergy forestrysystems, 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 ashort rotation coppicesystem 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 highenergy efficiency.[20]
Fuel
[edit]Biofuelis another option for using poplar as bioenergy supply. In the United States, scientists studied convertingshort rotation coppicepoplar 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 higherenergy recoverythan that from bioconversion.[22]
Art
[edit]Poplar was the most common wood used in Italy forpanel paintings;theMona Lisaand most famous earlyItalian Renaissancepaintings are on poplar.[citation needed]The wood is generally white, often with a slightly yellowish colour.
Somestringed instrumentsare made with one-piece poplar backs;violasmade in this fashion are said[citation needed]to have a particularly resonant tone. Similarly, though typically it is considered to have a less attractive grain than the traditionalsitka spruce,poplar is beginning to be targeted by someharpluthiersas a sustainable and even superior alternative for theirsound boards:[23]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.
Land management
[edit]Lombardy poplarsare frequently used as awindbreakaround agricultural fields to protect against wind erosion.
Agriculture
[edit]Logs from the poplar provide a growing medium forshiitakemushrooms.[24]
Phytoremediation
[edit]Poplar represents a suitable candidate forphytoremediationsince it has the ability to remove and store harmful pollutants in its trunk while also removing air pollution.[25]This plant has been successfully used to target many types of pollutants includingtrace element(TEs) in soil[26]andsewage sludge,[27][28]Polychlorinated Biphenyl(PCBs),[29]Trichloroethylene(TCE),[30]Polycyclic Aromatic Hydrocarbon(PAHs).[31]
Culture
[edit]Two notable poems in English lament the cutting down of poplars,William Cowper's "The Poplar Field" andGerard Manley Hopkins' "Binsey Poplarsfelled 1879 ".
InBillie Holiday's "Strange Fruit",she sings" Black bodies swinging in the southern breeze/Strange fruit hanging from the poplar trees… ".
The Odd Poplars Alley, inIași,Romania, is one of the spots whereMihai Eminescusought 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 ofKyivis named afterPopulus nigraasOsokorky,a local name.
References
[edit]- ^Joint Genome Institute,Populus trichocarpaArchived2 May 2008 at theWayback Machine
- ^abcdMeikle, R. D. (1984).Willows and Poplars of Great Britain and Ireland.BSBI Handbook No. 4.ISBN0-901158-07-0.
- ^abRushforth, K. (1999).Trees of Britain and rope.CollinsISBN0-00-220013-9.
- ^abKeeler, H. L. (1900).Our Native Trees and How to Identify Them.New York: Charles Scribner's Sons. pp. 410–412.
- ^Eckenwalder, J.E. (1996)."Systematics and evolution ofPopulus".In R.F. Stettler; H.D. Bradshaw; P.E. Heilman; T.M. Hinckley (eds.).Biology ofPopulusand its implications for management and conservation.Ottawa: NRC Research Press, National Research Council of Canada.ISBN9780660165066.
- ^Hamzeh, M., & Dayanandan, S. (2004). Phylogeny ofPopulus(Salicaceae) based on nucleotide sequences of chloroplast TRNT-TRNF region and nuclear rDNA.Amer. J. Bot.91: 1398-1408. AvailableonlineArchived29 January 2008 at theWayback Machine
- ^Eckenwalder, J.E. (2001). "Key to species and main crosses". In D.I. Dickmann; J.G. Isebrands; J.E. Eckenwalder; J. Richardson (eds.).Poplar culture in North America.Ottawa: NRC Research Press. pp. 325–330.ISBN978-0-660-18145-5.
- ^"PopulusL. ".Plants of the World Online,Kew Science. Accessed 8 September 2021.[1]Archived26 February 2023 at theWayback Machine
- ^Dickmann, Donald; Kuzovkina, Yulia (2008).Poplars and Willows in the World(PDF).The Food and Agriculture Organization of the United Nations. p. 27.ISBN978-92-5-107185-4.Archived(PDF)from the original on 8 August 2016.Retrieved24 March2020.
- ^Liu, Xia; Wang, Zhaoshan; Wang, Wei; Huang, Qinqin; Zeng, Yanfei; Jin, Yu; Li, Honglei; Du, Shuhui; Zhang, Jianguo (2022)."Origin and evolutionary history of Populus (Salicaceae): Further insights based on time divergence and biogeographic analysis".Frontiers in Plant Science.13.doi:10.3389/fpls.2022.1031087.ISSN1664-462X.PMC9815717.PMID36618663.
- ^ab<Vázquez-García, José & Muñiz-Castro, Miguel Angel & González, Rosa & Nieves-Hernández, Gregorio & Pulido, Maria & Hernández-Vera, Gerardo & Delgadillo, Osvaldo. (2019). "Populus primaveralepensissp. 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.Retrieved3 October2019.
- ^Martin-Garcia, J. "Patterns and monitoring of Sesia apiformis infestations in poplar plantations at different spatial scales".Journal of Applied Entomology.
- ^Yadav, Rakesh (2009). "High frequency direct plant regeneration from leaf, internode, and root segments of Eastern Cottonwood (Populus deltoides) ".Plant Biotechnology Reports.3(3): 175–182.doi:10.1007/s11816-009-0088-5.S2CID42796629.
- ^H. A. Shapiro (2007).The Cambridge Companion to Archaic Greece.Cambridge University Press. p. 69.ISBN978-1-139-82699-0.Archivedfrom the original on 17 July 2023.Retrieved22 November2015.
- ^Angier, Bradford(1974).Field Guide to Edible Wild Plants.Harrisburg, PA: Stackpole Books. p. 172.ISBN0-8117-0616-8.OCLC799792.
- ^Poplar cultivation in EuropeArchived3 November 2007 at theWayback Machine
- ^Aiken, Laura (18 April 2012)."Baking Bread Abroad".Bakers Journal.Archivedfrom the original on 8 August 2016.Retrieved11 June2016.
- ^Aylott, Matthew J.; Casella, E; Tubby, I; Street, NR; Smith, P; Taylor, G (2008)."Yield and spatial supply of bioenergy poplar and willow short-rotation coppice in the UK".New Phytologist.178(2 fvhc): 358–370.doi:10.1111/j.1469-8137.2008.02396.x.PMID18331429.S2CID35494995.
- ^Nassi; Di Nasso, N.; Guidi, W.; Ragaglini, G.; Tozzini, C.; Bonari, E. (2010). "Biomass production and energy balance of a twelve-year-old short-rotation coppice poplar stand under different cutting cycles".Global Change Biology Bioenergy.2(2): 89–97.doi:10.1111/j.1757-1707.2010.01043.x.S2CID86414864.
- ^Dou, C; Marcondes, W.; Djaja, J.; Renata, R.; Gustafson, R. (2017)."Can we use short rotation coppice poplar for sugar based biorefinery feedstock? Bioconversion of two-year-old poplar grown as short rotation coppice".Biotechnology for Biofuels.10(1): 144.doi:10.1186/s13068-017-0829-6.PMC5460468.PMID28592993.
- ^Dou, C; Chandler, D.; Resende, F.; Renata, R. (2017). "Fast pyrolysis of short rotation coppice poplar: an investigation in thermochemical conversion of a realistic feedstock for the biorefinery".Biotechnology for Biofuels.10(1): 144.doi:10.1021/acssuschemeng.7b01000.
- ^"Harps by Wm. Rees - WM REES HARP MYTH 8".Archived fromthe originalon 26 March 2012.Retrieved1 July2011.Rees Harps Website, "Harp Myth #8".
- ^Shiitake growth studies performed by RMITArchived3 January 2010 at theWayback Machine
- ^Doty, Sharon L.; Freeman, John L.; Cohu, Christopher M.; Burken, Joel G.; Firrincieli, Andrea; Simon, Andrew; Khan, Zareen; Isebrands, J. G.; Lukas, Joseph; Blaylock, Michael J. (5 September 2017)."Enhanced Degradation of TCE on a Superfund Site Using Endophyte-Assisted Poplar Tree Phytoremediation".Environmental Science & Technology.51(17): 10050–10058.Bibcode:2017EnST...5110050D.doi:10.1021/acs.est.7b01504.ISSN0013-936X.PMID28737929.
- ^Guidi Nissim, W.; Palm, E.; Mancuso, S.; Azzarello, E. (2018). "Trace element phytoextraction from contaminated soil: a case study under Mediterranean climate".Environmental Science and Pollution Research.25(9): 9114–9131.Bibcode:2018ESPR...25.9114G.doi:10.1007/s11356-018-1197-x.PMID29340860.S2CID3892759.
- ^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., landfillleachate
- ^Justin, MZ; Pajk, N; Zupanc, V; Zupanƒçiƒç, M (2010). "Phytoremediation of landfill leachate and compost wastewater by irrigation ofPopulusandSalix:Biomass and growth response ".Waste Management.30(6): 1032–42.Bibcode:2010WaMan..30.1032J.doi:10.1016/j.wasman.2010.02.013.PMID20211551.
- ^Meggo RE, Schnoor JL. Cleaning Polychlorinated Biphenyl (PCB) Contaminated Garden Soil by Phytoremediation. Environmental sciences. 2013;1(1):33-52
- ^Gordon, M; Choe, N; Duffy, J; et al. (1998)."Phytoremediation of trichloroethylene with hybrid poplars".Environmental Health Perspectives.106(Suppl 4): 1001–1004.doi:10.2307/3434144.JSTOR3434144.PMC1533336.PMID9703485.
- ^Spriggs, T.; Banks, M. K.; Schwab, P. (2005). "Phytoremediation of Polycyclic Aromatic Hydrocarbons in Manufactured Gas Plant–Impacted Soil".J. Environ. Qual.34(5): 1755–1762.Bibcode:2005JEnvQ..34.1755S.doi:10.2134/jeq2004.0399.PMID16151227.
- ^"Iași - the county of centuries-old trees".Agerpres.ro. 17 October 2017. Archived fromthe originalon 6 August 2019.Retrieved15 October2018.
External links
[edit]
Media related toPopulusat Wikimedia Commons
