{{short description|Botanical category of fruit}} {{Redirect|False fruit|artificial fruit|Food model}}
[[File:Pseudocarps (2943643065).jpg|thumb|right|A selection of accessory fruits (from left to right: pear, fig, and strawberry)]]
An '''accessory fruit''' is a fruit that contains tissue derived from plant parts other than the ovary. In other words, the flesh of the fruit develops not from the floral ovary, but from some adjacent tissue exterior to the carpel (for example, from receptacles or sepal). As a general rule, the accessory fruit is a combination of several floral organs, including the ovary. In contrast, true fruit forms exclusively from the ovary of the flower.<ref name="Esau">Esau, K. 1977. ''Anatomy of seed plants''. John Wiley and Sons, New York.</ref>
Accessory fruits are usually indehiscent, meaning that they do not split open to release seeds when they have reached maturity.<ref>{{Cite web|title=Glossary Details – The William & Lynda Steere Herbarium|url=http://sweetgum.nybg.org/science/glossary/glossary-details/?irn=1134|access-date=2021-03-17|website=sweetgum.nybg.org}}</ref>
==Incorporated organs== {{See also|Glossary of botanical terms}}
The following are examples of accessory fruits listed by the plant organ from which the accessory tissue is derived:<ref>Merriam Webster Collegiate Dictionary entries for [http://www.merriam-webster.com/dictionary/syconium ''syconium''], [http://www.merriam-webster.com/dictionary/accessory_fruit ''accessory fruit''], [http://www.merriam-webster.com/dictionary/core ''core''], and [http://www.merriam-webster.com/dictionary/strawberry ''strawberry''], Merriam-Webster, Inc., 2006</ref> {| class="wikitable" |+ Accessory Fruit Organs |- ! Organ !! Fruit |- | Hypanthium || apple, pear, rose hip |- | Involucre || pineapple |- | Peduncle || cashew apple |- | Perianth || ''anthocarps'' of the Nyctaginaceae |- | Receptacle || fig, mulberry, pineapple, strawberry |- | Calyx || eastern teaberry, rose apple |}
Fruit with fleshy seeds, such as pomegranate or mamoncillo, are not considered to be accessory fruits.<ref>{{Citation|last1=Holland|first1=D.|title=Pomegranate: Botany, Horticulture, Breeding|date=2009|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/9780470593776.ch2|work=Horticultural Reviews|pages=127–191|publisher=John Wiley & Sons, Ltd|language=en|doi=10.1002/9780470593776.ch2|isbn=978-0-470-59377-6|access-date=2021-11-28|last2=Hatib|first2=K.|last3=Bar-Ya'akov|first3=I.|url-access=subscription}}</ref>
== Examples == === Apples and pears === thumb|Apple section, showing seeds plus papery expression of the ovary, surrounded by tissue formed from ripening of the hypanthium.
The part of apples and pears that is consumed is, in fact, the hypanthium. The ovary is the papery core that surrounds the apple seeds. As the hypanthium ripens it forms the edible tissues.<ref name=":0">{{Cite book |last=Michaels |first=Tom |last2=Clark |first2=Matt |last3=Hoover |first3=Emily |last4=Irish |first4=Laura |last5=Smith |first5=Alan |last6=Tepe |first6=Emily |date=2022-06-20 |title= The Science of Plants |chapter=8.1 Fruit Morphology |chapter-url=https://open.lib.umn.edu/horticulture/chapter/8-1-fruit-morphology/ |language=en}}</ref>
=== Roses === For roses, the hypanthium is the tissue that composes the edible part of rosehips. Roses and apples are both members of the Rosaceae family; the fact that they have similar fruit morphology is a major consideration in placing them in the same taxonomic family.<ref name=":0" />
=== Strawberries === [[File:Nombreux akènes de fraise situés en surface ayant germé sur la fraise elle même.jpg|thumb|On this strawberry, the many pips located on the surface have germinated in a phenomenon known as vivipary. The pips of the strawberry are its true fruit.]]
The edible part of the strawberry is formed, as part of the ripening process, from the receptacle of the strawberry flower. The true fruits (hence, containing the seeds) are the roughly 200 pips (which are, technically, achenes, a true fruit that contains a single seed from a single ovary). These pips dot the exterior of the strawberry.<ref name=":1" />
=== Cashew apple === [[File:Cashew apples.jpg|thumb|The cashew 'apple' and its attached drupe, which contains the edible seed.]]
The cashew apple is an oval- or pear-shaped structure that develops from the pedicel and the receptacle of the cashew flower and is technically called a hypocarpium.<ref>{{cite journal |last1=Varghese |first1=T. |last2=Pundir |first2=Y. |year=1964 |title=Anatomy of the pseudocarp in ''Anacardium occidentale'' L. |journal=Proceedings of the Indian Academy of Sciences, Section B |volume=59 |issue=5 |pages=252–258 |doi=10.1007/BF03052341 |s2cid=83230755}}</ref><ref name="duke">{{cite web |author1=James A Duke |date=1983 |title=''Anacardium occidentale'' L. |url=https://hort.purdue.edu/newcrop/duke_energy/Anacardium_occidentale.html |access-date=10 December 2019 |publisher=Handbook of Energy Crops. (unpublished); In: NewCROP, New Crop Resource Online Program, Center for New Crops and Plant Products, Purdue University}}</ref><ref name="eb">{{cite web |date=7 April 2020 |title=Cashew |url=https://www.britannica.com/plant/cashew |access-date=8 May 2021 |publisher=Encyclopedia Britannica}}</ref> It ripens into a yellow or red structure about {{convert|5–11|cm|abbr=on|frac=4}} long.<ref name="morton">{{cite book |author=Morton |first=Julia F. |author-link=Julia Morton |url=https://hort.purdue.edu/newcrop/morton/cashew_apple.html |title=Cashew apple, ''Anacardium occidentale'' L. |publisher=Center for New Crops and Plant Products, Department of Horticulture and Landscape Architecture, Purdue University |year=1987 |isbn=978-0-9610184-1-2 |pages=239–240 |access-date=18 March 2007 |archive-url=https://web.archive.org/web/20070315023810/http://www.hort.purdue.edu/newcrop/morton/index.html |archive-date=15 March 2007 |url-status=live}}</ref><ref name="duke" /> The true fruit of the cashew tree is a kidney–shaped drupe that grows at the end of the cashew apple; the seed inside this drupe is the cashew nut of commerce.<ref name="morton" />
=== Pineapple === thumb|Pineapple in flower
The pineapple is formed when 50 to 200 unpollinated flowers coalesce in a spiral arrangement— the flowers form individually and then fuse as a single 'multiple fruit'. The ovaries develop into berries and the fruit forms around an intercalary spike. The intercalary inflorescence (cluster of flowers) results when the terminal cluster of flowers are left behind by the growth of the main axis of the plant. Each polygonal area on the pineapple's surface is an individual flower.<ref>{{Cite web |title=Plant Details – Information about Ananas comosus Plant |url=https://www.efloraofgandhinagar.in/plant-details.php?cateUrl=herb&plantUrl=ananas-comosus |access-date=2023-03-18 |website=efloraofgandhinagar.in}}</ref>
== Research == Current research has proposed that a single class of genes may be responsible for regulating accessory fruit formation and ripening.<ref>{{cite journal |last1=Ireland |first1=Hilary |last2=Yao |first2=Jia-Long |last3=Tomes |first3=Sumathi |last4=Sutherland |first4=Paul |last5=Nieuwenhuizen |first5=Niels |last6=Gunaseelan |first6=Kularajathevan |last7=Winz |first7=Robert |last8=David |first8=Karine |last9=Schaffer |first9=Robert |title=Apple SEPALLATA1/2-like genes control fruit flesh development and ripening |journal=The Plant Journal |date=13 December 2012 |volume=73 |issue=6 |pages=1004–1056 |doi=10.1111/tpj.12094 |pmid=23236986 |doi-access= }}</ref> A study using strawberries concluded that hormone signaling pathways involving gibberellic acid and auxin affect gene expression, and contribute to the initiation of accessory fruit development.<ref name=":1">{{cite journal |last1=Zhou |first1=Junhui |last2=Sittmann |first2=John |last3=Guo |first3=Lei |last4=Xiao |first4=Yuwei |last5=Huang |first5=Xiaolong |last6=Pulapaka |first6=Anuhya |last7=Liu |first7=Zhongchi |title=Gibberellin and auxin signaling genes RGA1 and ARF8 repress accessory fruit initiation in diploid strawberry |journal=Plant Physiology |date=March 2021 |volume=185 |issue=3 |pages=1059–1075 | pmid=33793929 | doi=10.1093/plphys/kiaa087 |pmc=8133647}}</ref> Metabolic modifications in different developing accessory fruit tissues are due to the varied distributions of compounds such as triterpenoids and steroids.<ref>{{cite journal |last1=Dashbaldan |first1=Soyol |last2=Rogowska |first2=Agata |last3=Pączkowski |first3=Cezary |last4=Szakiel |first4=Anna |title=Distribution of Triterpenoids and Steroids in Developing Rugosa Rose (Rosarugosa Thunb.) Accessory Fruit |journal=Molecules |date=25 August 2021 |volume=26 |issue=17 |page=5158 | pmid=34500591| doi=10.3390/molecules26175158 | pmc=8433923 |doi-access=free }}</ref>
==See also== * Aggregate fruit * Compound fruit * Multiple fruit
==References== {{Reflist}} {{Fruits}}
Category:Fruit morphology