Editing Pinus taeda

{{Short description|Species of conifer}}
{{Speciesbox
| image = Loblolly Pines South Mississippi.JPG
| image_caption = Characteristic appearance of loblolly pines, south Mississippi, USA
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Farjon, A. |date=2013 |title=''Pinus taeda'' |volume=2013 |page=e.T42420A2978958 |doi=10.2305/IUCN.UK.2013-1.RLTS.T42420A2978958.en |access-date=19 November 2021}}</ref>
| genus = Pinus
| parent = Pinus subsect. Australes
| display_parents = 3
| species = taeda
| authority = ([[Carl Linnaeus]], [[Species Plantarum|1753]])
| range_map = Pinus taeda distribution map.png
| range_map_caption = Natural range of loblolly pine
}}

'''''Pinus taeda''''', commonly known as '''loblolly pine''', is one of several [[pine]]s native to the [[Southeastern United States]], from [[East Texas]] to [[Florida]], and north to southern [[New Jersey]].<ref name="Flora">{{eFloras|1|200005364|Pinus taeda |family=Pinaceae |first=Robert |last=Kral}}</ref> The [[wood industry]] classifies the species as a [[southern yellow pine]].<ref name=baker/> [[U.S. Forest Service]] surveys found that loblolly pine is the second-most common species of tree in the [[United States]], after [[red maple]].<ref>{{cite web|last=Nix|first=Steve|title=Ten Most Common Trees in the United States|work=About.com Education |url=http://forestry.about.com/b/2012/07/21/ten-most-common-trees-in-the-united-states.htm|publisher=About.com Forestry|access-date=11 January 2013}}</ref> For its [[timber]], the pine species is regarded as the most commercially important tree in the Southeastern U.S.<ref>{{cite web|title=Loblolly Pine|url=http://www.ibiblio.org/pic/NCTrees/loblollypine.htm|publisher=Plant Information Center|access-date=27 March 2014}}</ref><ref>{{cite web|title=Loblolly pine|url=http://dendro.cnre.vt.edu/LandownerFactsheets/detail.cfm?Genus=Pinus&Species=taeda|publisher=Virginia Tech Forestry Department|access-date=27 March 2014}}</ref><ref>{{cite web|title=Loblolly Pine|url=http://www.treeimprovement.org/public/about/species-interest/loblolly-pine/loblolly-pine|publisher=Tree Improvement Programme|access-date=27 March 2014}}</ref> The common name loblolly is given because the pine species is found mostly in lowlands and swampy areas.<ref name=freedictionary>{{cite book|title=The American Heritage® Dictionary of the English Language|year=2000|publisher=Houghton Mifflin Company|url=http://www.thefreedictionary.com/loblolly|edition=4th}}</ref>

Loblolly pine is the first among over 100 species of ''[[Pinus]]'' to have its [[List of sequenced plant genomes|complete genome sequenced]]. As of March 2014, it was the organism having the largest sequenced genome size. Its genome, with 22 billion [[base pairs]], is seven times larger than [[human genome|that of humans]].<ref name=Zimin>{{cite journal|last1=Zimin|first1=Aleksey|last2=Stevens|first2=Kristian|display-authors=etal|title=Sequencing and Assembly of the 22-Gb Loblolly Pine Genome|journal=Genetics|date=Mar 2014|volume=196|issue=3|pages=875–890|doi=10.1534/genetics.113.159715|pmid=24653210| pmc=3948813 }}</ref><ref name=main>{{cite web|last=Main|first=Douglas|title=Scientists Sequence The Largest Genome To Date|url=http://www.popsci.com/article/science/scientists-sequence-largest-genome-date?dom=PSC&loc=poprail&lnk=6&con=scientists-sequence-the-largest-genome-to-date-|work=Popular Science|publisher=A Bonnier Corporation Company|access-date=27 March 2014|date=20 March 2014}}</ref> As of 2018, assembly of the [[axolotl]] genome (32Gb) displaced loblolly pine as the largest assembled genome.<ref name=Nowoshilow>{{cite journal | first1=Sergej Nowoshilow | last1=Eugene W. Myers |title=The axolotl genome and the evolution of key tissue formation regulators | journal=Nature | volume=554 | issue=7690 | pages=50–55 | year=2018 | doi=10.1038/nature25458 | pmid=29364872 | bibcode=2018Natur.554...50N | doi-access=free | hdl=21.11116/0000-0003-F659-4 | hdl-access=free }}</ref> The loblolly pine was selected as the official state tree of [[Arkansas]] in 1939.<ref>{{cite web |url=https://www.meettheusa.com/usa-facts/arkansas-facts |title=47 Arkansas Facts |publisher=Meet The USA |date=2022}}</ref>

==Description==
Loblolly pine can reach a height of {{convert|30|-|35|m|abbr=off|ft|sp=us}} with a diameter of {{cvt|0.4|-|1.5|m|ft}}. Exceptional specimens may reach {{cvt|50|m|ft}} tall, the largest of the southern pines. Its needles are in bundles (fascicles) of three, sometimes twisted, and measure {{convert|12|-|22|cm|abbr=off|frac=4|sp=us}} long, an intermediate length for southern pines, shorter than those of the [[longleaf pine]] or [[slash pine]], but longer than those of the [[Pinus echinata|shortleaf pine]] and [[Pinus glabra|spruce pine]]. The needles usually last up to two years before they fall, which gives the species its evergreen character.<ref name=":0">{{Cite book |last=Grimm |first=William Carey |title=The Book of Trees |publisher=The Stockpole Company |year=1966 |location=Harrisburg, Pennsylvania |pages=48 |language=en}}</ref> Needles are yellowish-green to grayish green.<ref name=":0" />

Although some needles fall throughout the year due to severe weather, insect damage, and drought, most needles fall during the autumn and winter of their second year. The [[Conifer cone|seed cones]] are green, ripening pale buff-brown, {{cvt|7|-|13|cm|in|frac=4}} in length, {{cvt|2|-|3|cm|in|frac=4}} broad when closed, opening to {{cvt|4|-|6|cm|in|frac=4}} wide, each scale bearing a sharp spine {{convert|3|to|6|mm|frac=8|2|sp=us}} long.<ref name="Flora"/><ref name="Farjon">Farjon, A. (2005). ''Pines: Drawings and Descriptions of the Genus'' Pinus, ed.2. Brill, Leiden {{ISBN|90-04-13916-8}}.</ref>

Bark is reddish brown and deeply fissured into irregular, broad, scaly plates on older trees. Branches are reddish-brown to dark yellowish brown.<ref name=":0" />

Loblolly pines are one of the fastest growing pines making it a valuable species in the lumber industry. The lumber marketed as yellow pine lumber and similar usage to other southern pines such as the more stronger Longleaf and Shortleaf pines. They are also used as pulpwood.<ref name=":0" /> It grows at an average of 2 feet per year.<ref>Gonzalez-Benecke, C. A., Martin, T. A., Clark, A. I., & Peter, G. F. (2010). Water availability and genetic effects on wood properties of loblolly pine (Pinus taeda). Canadian Journal of Forest Research, 40(12), 2265–2277. https://doi.org/10.1139/X10-162</ref> The tallest loblolly pine currently known, which is {{cvt|51.4|m|ft}} tall, and the largest, which measures {{convert|42|m3|abbr=off|sp=us}} in volume, are in [[Congaree National Park]].<ref name="Gymnosperm">{{Gymnosperm Database |family=Pinaceae |genus=Pinus |species=taeda}}</ref>

<gallery widths="200px" heights="200px">
File:Pinus taeda cones.jpg|Mature unopened female cones
File:Tree Types and Barks 004.jpg|Bark on a mature tree
File:P. taeda old growth.jpg|A gigantic old-growth loblolly pine, note human for scale
</gallery>

==Etymology and taxonomy==
The word "loblolly" is a combination of "lob", referring to thick, heavy bubbling of cooking [[porridge]], and "lolly", an old British dialect word for "broth, soup, or any other food boiled in a pot"{{citation needed|date=May 2025}}. In the southern United States, the word is used to mean "a mudhole; a mire," a sense derived from an allusion to the consistency of porridge. Hence, the pine is named as it is generally found in lowlands and swampy areas.<ref name=freedictionary/> Loblolly pines grow well in acidic clay soil, which is common throughout the South, thus are often found in large stands in rural places.

Other old names, now rarely used, include oldfield pine due to its status as an [[Ruderal species|early colonizer]] of abandoned fields; bull pine due to its size (several other [[yellow pine]]s are also often so named, especially large isolated specimens); rosemary pine due to loblolly's distinctive fragrance compared to the other southern pines; and North Carolina pine.<ref name="Moore2008">{{cite book |author1=Moore, Gerry |author2=Kershner, Bruce |author3=Tufts, Craig |author4=Mathews, Daniel |author5=Nelson, Gil |author6=Spellenberg, Richard |author7=Thieret, John W. |author8=Purinton, Terry |author9=Block, Andrew |title=National Wildlife Federation Field Guide to Trees of North America |publisher=Sterling |location=New York |year=2008 |page=73 |isbn=978-1-4027-3875-3}}</ref><ref name=":0" />

For the [[scientific name]], ''[[wikt:Pinus|Pinus]]'' is the Latin name for the pines and ''[[wikt:taeda|taeda]]'' refers to the resinous wood.<ref>{{Cite web |url=http://www.biosurvey.ou.edu/shrub/pita.htm |title=Oklahoma Biological Survey: ''Pinus taeda'' L. |access-date=2010-04-29 |archive-url=https://web.archive.org/web/20100622042503/http://www.biosurvey.ou.edu/shrub/pita.htm |archive-date=2010-06-22 |url-status=dead }}</ref>

==Ecology==
With the advent of [[wildfire suppression]], loblolly pine has become prevalent in some parts of the Deep South that were once dominated by longleaf pine and, especially in northern [[Florida]], [[Pinus elliottii|slash pine]].<ref>Richardson, D. M., & Rundel, P. W. (1998). Ecology and biogeography of Pinus: an introduction. Pages 3–46 in Richardson, D. M., ed. ''Ecology and biogeography of Pinus''. Cambridge University Press {{ISBN|0-521-55176-5}}.</ref>

Its rate of growth is rapid, even among the generally fast-growing southern pines. The yellowish, [[resin]]ous wood is prized for lumber, but is also used for [[wood pulp]]. This tree is commercially grown in extensive [[Plantation#Forestry|plantations]].<ref name=baker>{{Silvics |volume=1 |genus=Pinus |species=taeda |first1=James B. |last1=Baker |first2=0. Gordon |last2=Langdon}}</ref>

Loblolly pine is the pine of the [[Lost Pines Forest]] around [[Bastrop, Texas]], and in [[McKinney Roughs Nature Park]] along the [[Colorado River (Texas)|Texas Colorado River]]. These are [[Disjunct distribution|isolated populations]] on areas of [[acid]]ic [[sand]]y soil, surrounded by [[alkali]]ne [[clay]]s that are poor for pine growth.

A study using loblolly pines showed that higher atmospheric carbon dioxide levels may help the trees to endure ice storms better.<ref>[http://www.livescience.com/environment/060818_loblolly_co2.html Greenhouse Gas Good for Some Trees] - LiveScience.com</ref>

==Notable trees==
The famous "[[Eisenhower Tree]]" on the 17th hole of [[Augusta National Golf Club]] was a loblolly pine. [[President of the United States|U.S. President]] [[Dwight D. Eisenhower]], an Augusta National member, hit the tree so many times that at a 1956 club meeting, he proposed that it be cut down. Not wanting to offend the President, the club's chairman, Clifford Roberts, immediately adjourned the meeting rather than reject the request outright. In February 2014, an [[February 2014 winter storm|ice storm]] severely damaged the Eisenhower Tree. The opinion of [[arborist]]s was that the tree could not be saved and should be removed, which it subsequently was.<ref>{{cite news|url=http://chronicle.augusta.com/sports/golf/2014-02-16/masters-landmark-ikes-tree-suffers-major-damage-removed?v=1392572685/|title=Masters landmark Ike's Tree suffers major damage, removed|work=[[The Augusta Chronicle]]|date=February 16, 2014|access-date=February 17, 2014|url-status = dead | archive-url = https://web.archive.org/web/20140223031217/http://chronicle.augusta.com/sports/golf/2014-02-16/masters-landmark-ikes-tree-suffers-major-damage-removed?v=1392572685/ | archive-date = 23 February 2014 | first = John | last = Boyette}}</ref>

The "Morris Pine" is located in southeastern Arkansas; it is over 300 years old with a diameter of {{cvt|142|cm|in}} and a height of {{cvt|35.7|m|ft}}.<ref>{{cite web|url=http://www.nativetreesociety.org/bulletin/b1_1/B_ENTS_v1_01_sec6_SBT02.pdf
|author=Bragg, Don C|title=The Morris Pine|publisher= Bulletin of the Eastern Native Tree Society. Volume 1 (Summer 2006): 20|access-date=2012-11-13}}</ref>

Loblolly pine seeds were carried aboard the [[Apollo 14]] flight. On its return, the seeds were planted in several locations in the US, including the grounds of the [[White House]]. {{As of|2016}}, a number of these [[moon tree]]s remain alive.<ref name="Williams">{{Cite web| url=http://nssdc.gsfc.nasa.gov/planetary/lunar/moon_tree.html| title=The "Moon Trees"| first=David R.| last=Williams| publisher=[[NASA]]| work=[[Goddard Space Flight Center]]| date=28 July 2009| access-date=8 March 2016}}</ref>

==Genome==
Pines are the most common [[conifers]] and the genus ''Pinus'' consists of more than 100 species. Sequencing of their genomes remained a huge challenge because of the high complexity and size.<ref>{{cite journal|last=Neves|first=Leandro G.|author2=Davis, John M. |author3=Barbazuk, William B. |author4= Kirst, Matias |title=Whole-exome targeted sequencing of the uncharacterized pine genome|journal=The Plant Journal|year=2013|volume=75|issue=1|pages=146–156|doi=10.1111/tpj.12193|pmid=23551702|doi-access=free}}</ref> Loblolly pine became the first species with its complete genome sequenced.<ref name=Zimin/><ref>{{cite journal|last=Neale|first=David B|display-authors=etal|title=Decoding the massive genome of loblolly pine using haploid DNA and novel assembly strategies|journal=Genome Biology|date=Mar 2014|volume=15|issue=3|pages=R59|doi=10.1186/gb-2014-15-3-r59|pmid=24647006|pmc=4053751 |doi-access=free }}</ref> This was the largest genome assembled until 2018, when the [[axolotl]] genome (32Gb) was assembled.<ref name=Nowoshilow/>

The loblolly pine genome is made up of 22.18 billion base pairs, which is more than seven times that of humans.<ref name=main/> Conifer genomes are known to be full of [[repetitive DNA]], which make up 82% of the genome in loblolly pine (compared to only 50% in humans). The number of genes is estimated at 50,172, of which 15,653 are already confirmed. Most of the genes are [[Gene duplication|duplicates]]. Some genes have the longest [[introns]] observed among fully sequenced plant genomes.<ref name=wegrzyn>{{cite journal|last=Wegrzyn|first=J. L.|author2=Liechty, J. D.|author3=Stevens, K. A.|author4=Wu, L.-S.|author5=Loopstra, C. A.|author6=Vasquez-Gross, H. A.|author7=Dougherty, W. M.|author8=Lin, B. Y.|author9=Zieve, J. J.|author10=Martinez-Garcia, P. J.|author11=Holt, C.|author12=Yandell, M.|author13=Zimin, A. V.|author14=Yorke, J. A.|author15=Crepeau, M. W.|author16=Puiu, D.|author17=Salzberg, S. L.|author18=de Jong, P. J.|author19=Mockaitis, K.|author20=Main, D.|author21=Langley, C. H.|author22=Neale, D. B.|title=Unique Features of the Loblolly Pine (Pinus taeda L.) Megagenome Revealed Through Sequence Annotation|journal=Genetics|year=2014|volume=196|issue=3|pages=891–909|doi=10.1534/genetics.113.159996|pmid=24653211| pmc=3948814 }}</ref>

==Inbreeding depression==
[[Gymnosperm]]s are predominantly [[outcrossing]], but lack genetic [[Self-incompatibility in plants|self-incompatibility]]. Loblolly pine, like most gymnosperms, exhibits high levels of [[inbreeding depression]], especially in the embryonic stage. The loblolly pine harbors an average load of at least eight lethal equivalents.<ref name="pmid10790407">{{cite journal |vauthors=Remington DL, O'Malley DM |title=Whole-genome characterization of embryonic stage inbreeding depression in a selfed loblolly pine family |journal=Genetics |volume=155 |issue=1 |pages=337–48 |year=2000 |doi=10.1093/genetics/155.1.337 |pmid=10790407 |pmc=1461072 }}</ref> A lethal equivalent is the number of deleterious genes per haploid genome whose cumulative effect is the equivalent of one lethal gene. The presence of at least eight lethal equivalents implies substantial inbreeding depression upon self-fertilization.{{Citation needed|date=April 2021}}

==See also==
* [[Sonderegger pine]], a hybrid between loblolly and [[Longleaf pine|longleaf]] species

==References==
{{Reflist|30em}}

==External links==
* {{Wikispecies-inline|Pinus taeda|''Pinus taeda''}}
* {{Commons category-inline|Pinus taeda|''Pinus taeda''}}

{{Taxonbar|from=Q368248}}
{{Authority control}}

[[Category:Least concern plants]]
[[Category:Pinus|taeda]]
[[Category:Plants described in 1753]]
[[Category:Symbols of Arkansas]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Trees of humid continental climate]]
[[Category:Trees of Northern America]]