Editing Citrus (section)

== Description ==

=== Tree ===

''Citrus'' plants are large shrubs or small to moderate-sized trees, reaching {{convert|5|–|15|m|abbr=on}} tall, with [[Spine (botany)|spiny]] shoots and alternately arranged [[evergreen]] [[leaf|leaves]] with an entire margin.<ref>{{Cite web |url=https://crfg.org/wp-content/uploads/CITRUS-PRUNING-Presentation.pdf |title=Citrus Pruning |last=Del Hotal |first=Tom |website=California Rare Fruit Growers}}</ref> The [[flower]]s are solitary or in small [[corymb]]s, each flower {{convert|2|–|4|cm|abbr=on}} diameter, with five (rarely four) white petals and numerous stamens; they are often very strongly scented, due to the presence of essential oil glands.<ref name="Ortiz 2002">{{cite book |last1=Ortiz |first1=Jesus M. |editor1-last=Di Giacomo |editor1-first=Angelo |editor2-last=Dugo |editor2-first=Giovanni |title=Citrus: The Genus ''Citrus'' |date=2002 |publisher=Taylor & Francis |isbn=978-0-2032-1661-3 |pages=16–35 |url=https://books.google.com/books?id=OLaykfpqSaYC&dq=Citrus+genus&pg=PP1 |chapter=Botany: taxonomy, morphology and physiology of fruits, leaves and flowers}}</ref>

=== Fruit ===

{{main list|List of citrus fruits}}

[[File:Structure of an orange.svg|thumb|upright=1.2|Structure of the botanical [[hesperidium]] ]]

The fruit is a [[hesperidium]], a specialised berry with multiple [[carpel]]s, globose to elongated,<ref name="Ortiz 2002"/><ref name="janick">{{cite web |author=Janick, Jules |date=2005 |publisher=[[Purdue University]] Tropical Horticulture Lecture 32 |url=http://www.hort.purdue.edu/newcrop/tropical/lecture_32/lec_32.html |title=Citrus|access-date=28 February 2020|archive-url=https://web.archive.org/web/20050624235046/http://www.hort.purdue.edu/newcrop/tropical/lecture_32/lec_32.html|archive-date=24 June 2005}}</ref> {{convert|4|–|30|cm|abbr=on}} long and {{convert|4|–|20|cm|abbr=on}} diameter, with a leathery rind or "peel" called a [[pericarp]]. The outermost layer of the pericarp is an "exocarp" called the [[flavedo]], commonly referred to as the [[Zest (ingredient)|zest]]. The middle layer of the pericarp is the mesocarp, which in citrus fruits consists of the white, spongy albedo or pith. The innermost layer of the pericarp is the endocarp. This surrounds a variable number of [[carpel]]s, shaped as radial segments. The seeds, if present, develop inside the carpels. The space inside each segment is a [[locule]] filled with [[juice vesicles]], or pulp. From the endocarp, string-like "hairs" extend into the locules, which provide nourishment to the fruit as it develops.<ref name="Ortiz 2002"/><ref>{{cite web |url=http://www.botgard.ucla.edu/html/botanytextbooks/economicbotany/Citrus/b1241tx.html |title=Citrus fruit diagram |work=ucla.edu |url-status=dead |archive-url=https://web.archive.org/web/20121003070722/http://www.botgard.ucla.edu/html/botanytextbooks/economicbotany/Citrus/b1241tx.html |archive-date=3 October 2012}}</ref> The genus is commercially important with [[cultivar]]s of many species grown for their fruit. Some cultivars have been developed to be easy to peel and seedless, meaning they are [[parthenocarpy|parthenocarpic]].<ref name=janick/>

The fragrance of citrus fruits is conferred by [[flavonoid]]s and [[limonoid]]s in the rind. The flavonoids include various [[flavanone]]s and [[flavones]].<ref>{{cite web |url=http://www.jstage.jst.go.jp/article/bbb/70/1/70_178/_article |title=Flavonoid Composition of Fruit Tissues of Citrus Species |access-date=5 July 2011 |archive-url=https://web.archive.org/web/20070528015124/http://www.jstage.jst.go.jp/article/bbb/70/1/70_178/_article |archive-date=28 May 2007 |url-status=dead}}</ref> The carpels are juicy; they contain a high quantity of [[citric acid]], which with other organic acids including [[ascorbic acid]] (vitamin C) give them their characteristic sharp taste.<ref name="Abolore Tsegaye 2023">{{cite book |last1=Abolore |first1=Rasaq S. |last2=Tsegaye |first2=Bahiru |last3=Jaiswal |first3=Swarna |last4=Jaiswal |first4=Amit K. |title=Value-Addition in Beverages through Enzyme Technology |chapter=An overview of industrial enzymes in beverage production and processing |publisher=Elsevier |year=2023 |isbn=978-0-323-85683-6 |doi=10.1016/b978-0-323-85683-6.00013-2 |pages=1–26 (section 1.2.3.2 Citrus juice)}}</ref> ''Citrus'' fruits are diverse in size and shape, as well as in color and flavor, reflecting their biochemistry;<ref name="GRIN">{{cite web |url=http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?2640 |title=Species list in GRIN for genus ''Citrus'' |author=GRIN |work=Taxonomy for Plants |publisher=[[United States Department of Agriculture|USDA]], [[Agricultural Research Service|ARS]], National Genetic Resources Program |location=National Germplasm Resources Laboratory, [[Beltsville, Maryland]] |access-date=6 January 2011 |author-link=Germplasm Resources Information Network |url-status=dead |archive-url=https://web.archive.org/web/20090120155922/http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?2640 |archive-date=20 January 2009}}</ref><ref name="Luro Curk 2017">{{cite book |last1=Luro |first1=François |last2=Curk |first2=Franck |last3=Froelicher |first3=Yann |last4=Ollitrault |first4=Patrick |title=AGRUMED: Archaeology and history of citrus fruit in the Mediterranean |chapter=Recent insights on Citrus diversity and phylogeny |publisher=Publications du Centre Jean Bérard |date=2017 |isbn=978-2-918887-77-5 |doi=10.4000/books.pcjb.2169}}</ref> for instance, grapefruit is made bitter-tasting by a flavanone, [[naringin]].<ref name="Abolore Tsegaye 2023"/>


<gallery mode=packed heights=130 caption="''Citrus'' fruits are diverse in size, shape, color, and flavor.">
File:Ichangfruit.jpg|[[Ichang papeda]]
File:Quinotos.jpg|[[Kumquat]], with a [[seed]] inside one of the [[carpel]]s
File:Buddhas hand 1.jpg|[[Buddha's hand]]
File:Citrus australasica red whole.jpg|Red [[finger lime]]
File:Fortpolyandra.jpg|[[Clymenia (plant)|Clymenia]]
</gallery>