View source for Luffa

{{Short description|Genus of vines}}
{{About|the plant|the sponge made from it|Exfoliation (cosmetology)#Loofah|}}
{{Automatic taxobox
| image = Luffa aegyptica.jpg
| image_caption = Egyptian luffa with nearly mature fruit
| display_parents = 2
| taxon = Luffa
| authority = [[Philip Miller|Mill.]]<ref name="OriginOfNomenclature" />
| subdivision_ranks = Species
| subdivision =
* ''[[Luffa acutangula]]'' (L.) Roxb. (angled luffa, ridged luffa, vegetable gourd)
* ''[[Luffa aegyptiaca]]'' Mill. (smooth luffa, Egyptian luffa, dishrag gourd, gourd loofa)
* ''[[Luffa astorii]]'' Svenson
* ''[[Luffa echinata]]'' Roxb.
* ''[[Luffa graveolens]]'' Roxb.
* ''[[Luffa operculata]]'' (L.) Cogn. (wild loofa, sponge cucumber)
* ''[[Luffa quinquefida]]'' (Hook. & Arn.) Seem.
* ''[[Luffa saccata]]'' F.Muell. ex I.Telford
* ''[[Luffa sepium]]'' (G.Mey.) C.Jeffrey
| subdivision_ref = <ref name = "POWO" />
| synonyms =
*''Poppya'' <small>[[Neck.]]</small>
*''Trevouxia'' <small>[[Scop.]]</small>
*''Turia'' <small>[[Forssk.]] ex J.F.Gmel.</small>
|synonyms_ref = <ref name = "POWO">{{cite POWO |id=30179638-2 |title=''Luffa'' Mill. |accessdate=26 October 2023}}</ref>
}}
'''''Luffa''''' is a genus of tropical and subtropical [[vine]]s in the [[pumpkin]], [[Squash (plant)|squash]] and [[gourd]] family ([[Cucurbitaceae]]).
In everyday non-technical usage, the luffa, also spelled '''loofah'''<ref>{{Cite web |title=loofah {{!}} Collins Dictionary |url=https://www.collinsdictionary.com/dictionary/english/loofah}}</ref> or less frequently '''loofa''',<ref>{{Cite web |title=loofa {{!}} Collins Dictionary |url=https://www.collinsdictionary.com/dictionary/english/loofa}}</ref> usually refers to the fruits of the species ''[[Luffa aegyptiaca]]'' and ''[[Luffa acutangula]]''. It is cultivated and eaten as a vegetable, but must be harvested at a young stage of development to be edible. The vegetable is popular in India, China, Nepal, Bhutan, Bangladesh and Vietnam.<ref>{{cite web|last=Christman|first=Steve|date=March 13, 2010|url=http://www.floridata.com/ref/l/luff_aeg.cfm |title=''Luffa aegyptiaca''|website= Floridata.com|access-date=September 15, 2013|url-status=live|archive-date=August 1, 2013|archive-url=https://web.archive.org/web/20130801212039/http://www.floridata.com/ref/l/luff_aeg.cfm}}</ref> When the fruit fully ripens, it becomes too fibrous for eating. The fully developed fruit is the source of the loofah [[Sponge (tool)|scrubbing sponge]].
==Names==
The name ''luffa'' was taken by European botanists in the 17th century from the [[Arabic]] name {{lang|arz|لوف}} ''lūf''.<ref name="OriginOfNomenclature">The plant name "luffa" was introduced to Western botany nomenclature by the botanist [[Johann Vesling]] (died 1649), who visited [[Egypt]] in the late–1620s and described the plant under cultivation with artificial irrigation in Egypt. In 1706 the botanist [[Joseph Pitton de Tournefort]] introduced the formal botany genus name "Luffa". Tournefort referred to Veslingius's earlier description and reiterated that "Luffa Arabum" is a plant from Egypt in the cucumber family. In establishing the genus ''Luffa'', Tournefort identified just one member species and called it "Luffa Arabum". His 1706 article includes detailed drawings of this species (which is now called ''Luffa aegyptiaca''). The species is native to tropical Asia but has been under cultivation in Egypt since late medieval times. The botanist [[Peter Forsskål]] visited Egypt in the early–1760s and noted that it was called {{lang|ar|ليف}} ''lūf'' in Arabic. In the 18th century the botanist [[Carl Linnaeus|Linnaeus]] adopted the name ''luffa'' for this species but assigned it to the genus ''[[Momordica]]'', and did not use a separate genus ''Luffa''. More refs on ''Luffa'' in 18th century botanical nomenclature: [https://books.google.com/books?id=iVsLAAAAIAAJ&dq=Tournefort+luffa&pg=PA377 "A commentary on Loureiro's "Flora Cochinchinensis" "], by E.D. Merrill, year 1935, in ''Transactions of American Philosophical Society'' volume 24 part 2, pp 377-378. [http://portail.atilf.fr/cgi-bin/getobject_?p.69:116./var/artfla/encyclopedie/textdata/IMAGE/ ''Luffa'' @ ATILF] {{Webarchive|url=https://web.archive.org/web/20131017051352/http://portail.atilf.fr/cgi-bin/getobject_?p.69%3A116.%2Fvar%2Fartfla%2Fencyclopedie%2Ftextdata%2FIMAGE%2F |date=2013-10-17 }} and [https://archive.org/stream/histoiredelacad06laca#page/83/mode/1up "''Suite de l'Etablissement de Quelques Nouveaux Genres de Plantes''"], by J.P. de Tournefort (1706) in ''Mémoires de l'Academe Royale des Sciences année 1706''.</ref>
In [[North America]] it is sometimes known as "Chinese [[okra]]",<ref>{{Cite web |last=Turiano |first=John Bruno |date=2014-03-26 |title=What the Heck Is Chinese Okra? A Guide to the Vegetable |url=https://westchestermagazine.com/food/what-the-heck-is-chinese-okra/ |access-date=2023-07-14 |website=Westchester Magazine |language=en-US}}</ref> and in Spanish as ''estropajo''.<ref>{{Cite web |title=Luffa aegyptiaca - ficha informativa |url=http://www.conabio.gob.mx/malezasdemexico/cucurbitaceae/luffa-aegyptiaca/fichas/ficha.htm |access-date=2023-07-14 |website=www.conabio.gob.mx}}</ref>
==Uses==
===Fibers===
[[File:Loofah.jpg|thumb|A bathroom loofa sponge]]
The fruit section of ''L. aegyptiaca'' may be allowed to mature and used as a bath or kitchen [[sponge (material)|sponge]] after being processed to remove everything except the network of [[xylem]] fibers. If the loofah is allowed to fully ripen and then dried on the vine, the flesh disappears, leaving only the fibrous skeleton and seeds, which can be easily shaken out. Marketed as ''luffa'' or ''loofah'', the sponge is used as a body scrub in the shower.
In Paraguay, panels are made out of luffa combined with other vegetable matter and recycled plastic. These can be used to create furniture and construct houses.<ref>[https://web.archive.org/web/20121016194813/http://www.rolexawards.com/profiles/laureates/elsa_zaldvar/project Recyclable Homes]; 2008 Rolex Awards for Enterprise. Archived 2012-10-16 at the [[Wayback Machine]].</ref>
===Food===
Luffa is a popular food item. There are various ways to prepare it including in soups or stir frys.
====Indian subcontinent====
{{Further|List of plants used in Indian cuisine}}
[[File:బీరకాయ పప్పు.jpg|thumb|Ridge gourd with [[mung bean]] made in a house in [[Vijayawada]], Andhra Pradesh, India]]
[[File:Ridge gourd( beerakai ).jpg|thumb|left|''Beerakaya pulusu'' curry ingredients]]
In [[Hindi]]-speaking [[North India]] states, it is called ''torai'' ({{lang|hi|तोरई}}), and cooked as vegetable. In eastern-UP it is also called ''nenua'' while in central/Western India, specially in Madhya Pradesh, it is called ''gilki'' ({{lang|hi|गिल्की}}). ''Torai'' is reserved for ridge gourd and is less popular than ''gilki'' in central western India.
In [[Punjabi language|Punjabi]]-speaking [[Punjab]], sponge gourd is called ''tori'' (ਤੋਰੀ), while ridged gourd is called ''ram tori'' (ਰਾਮ ਤੋਰੀ) and the fruit and flowers are mostly used in dishes.
In [[Bhojpuri language|Bhojpuri]] speaking regions, it is called ''ghiura'' (घिउरा). Apart from the fruit of the vegetable, flowers are also used as a vegetable as ''chokha'', ''tarua'', ''pakoda'', etc.
In [[Nepal]] and [[Nepali language]] speaking Indian states, sponge /smooth gourd is called ''ghiraula'' (घिरौंला), while the ridged variety is called ''pate ghiraula'' (पाटे घिरौंला). Both are popular vegetables usually cooked with tomatoes, potatoes and served with rice.
In [[Gujarat]], ridge gourd and sponge gourd are known as ''turya'' (તુરીયા) and ''galka'' (ગલકા) in [[Gujarati language|Gujarati]]  respectively. Ridge gourd is called ''ghissori'' or ''ghissora'' (ઘિસ્સોરી/ઘિસ્સોરા) in [[Kutchi language| Kutchi]]. They are simple yet popular vegetables, usually made with a plentiful tomato gravy and garnished with green chillies and fresh coriander. When cooked roti is shredded by hand and mixed into it, it is colloquially known as "rotli shaak ma bhuseli". Alternatively, this dish is also eaten mixed with plain cooked rice.
In [[Bengali language|Bengali]]-speaking [[Bangladesh]] and the Indian state of [[West Bengal]], ridge gourd is called ''jhinge'' ({{lang|bn|ঝিঙ্গে}}), while sponge gourd is known as ''dhundhul'' ({{lang|bn|ধুঁধুল}}), both being popular vegetables. They are eaten, fried or cooked with shrimp, fish, or meat.
In the [[Odia language|Odia]] language of [[Odisha]], ridge gourd ([[luffa acutangula]]) is known as ''janhi'' ({{lang|or|ଜହ୍ନି}}), while sponge gourd ([[luffa aegyptiaca]]) is called ''tarada''({{lang|or|ତରଡ଼ା}}), both accompanying many vegetarian and non-vegetarian dishes, most notably in dishes like "khira [[santula]]", where it is boiled with minuscule spices and simmered in milk. Another popular version involves mashing it in groundnut oil, herbs, peanuts and topping it with the peeled skin pieces.
In [[Assamese language|Assamese]] speaking areas of [[Assam]], it is called ''bhula'' (ভোল, [[luffa aegyptiaca]]) and is cooked with sour fish curry along with ''[[taro]]''. A related species is called ''jika'' (জিকা, [[Luffa acutangula]]), which is used as a vegetable in a curry, chutney and stir fry .<ref>{{Cite web|url=http://www.rumicooks.com/2016/10/fish-with-colocasia-and-sponge-gourd.html|title=Fish with colocasia and sponge gourd {{!}} Bhul kosu aru mas|access-date=2019-05-21}}</ref>
In [[Tamil language|Tamil]] language of [[Tamil Nadu]], ''Luffa acutangula'' (ridged gourd) is called ''peerkangai'' (பீர்க்கங்காய்) and ''Luffa aegyptiaca'' / ''Luffa cylindrica'' (sponge gourd) is called ''nurai peerkankai'' (நுரை  பீர்க்கங்காய்) and are used as vegetables to make ''peerkangai [[kootu]]'',<ref>{{Cite web|url=https://southindianfoods.in/peerkangai-kootu-ridge-gourd-kootu.html|title=Peerkangai kootu {{!}} Ridge gourd kootu|website=southindianfoods.in|access-date=2019-05-21}}</ref> ''[[poriyal]]'', and ''[[thogayal]]''.<ref>{{Cite web|url=https://www.saffrontrail.com/peerkangai-tuvaiyal-recipe/|title=Peerkangai Tuvaiyal|website=Saffron Trail|date=25 April 2006 |language=en-US|access-date=2019-05-21}}</ref> Even the skin is used to make chutney.
In [[Karnataka]]'s [[Kannada language|Kannada]] speaking areas, sponge gourd is better known as ''tuppa dahirekayi'' (ಟುಪ್ಪಾದ ಹೀರೆಕಾಯಿ), literally translating to "buttersquash" in English, while ridge gourd is known as ''hirekayi'' (ಹೀರೆಕಾಯಿ) in standard [[Kannada language| Kannada]]. Naturally growing in this region, it's consumed when it is still tender and green. It is used as a vegetable in curries, but also as a snack, ''bhajji'', dipped in chickpea batter and deep fried.
In [[Tulu language]], ridge gourd is known as Peere(ಪೀರೆ) and is used to prepare chutney and ajethna.<ref>{{Cite web|url=https://udupi-recipes.com/2016/02/ridge-gourd-chutney-without-coconut.html|title=Ridge Gourd chutney without coconut|website=udupi-recipes.com|date=23 February 2016|access-date=10 January 2020}}</ref>
In both [[Telangana]] and [[Andhra Pradesh]] [[Telugu language|Telugu]] dialects, ridge gourd is generally called ''beerakaya'' (బీరకాయ), while sponge gourd is called ''nethi beerakaya'' (సేతి బీరకాయ). It is used in making Dal, Fry, Roti Pacchadi, and wet curry.
In [[Malayalam]] language of [[Kerala]], ridge gourd is commonly called ''peechinga'' (പീച്ചിങ്ങ) and ''poththanga'' in the [[Palakkad]] dialect, while sponge gourd is called ''Eeṇilla peechinga'' (ഏണില്ല പീച്ചിങ്ങ). It is also used as a vegetable, cooked with dal or stir fried. The fully matured fruit is used as a natural scrub in rural Kerala. In some places such as [[Wayanad]], it grows as a creeper on fences.
In [[Marathi language|Marathi]]-speaking [[Maharashtra]], its called {{lang|mr|dodka}} (दोडका, ridge gourd luffa) and ''ghosaļ'' (घोसाळ ,smooth/sponge luffa) which are common vegetables, prepared with either crushed dried peanuts or with beans.
In [[Meitei language]] of [[Manipur]], ridge gourd is called {{lang|mni|sebot}} (ꯁꯦꯕꯣꯠ) and sponge gourd is called {{lang|mni| sebot hekpa}} (ꯁꯦꯕꯣꯠ ꯍꯦꯀꯞ), which is cooked with other ingredients like potato, dried fish, fermented fish and served. They are also steamed before consuming or crushed ({{lang|mni|ironba}}) with other ingredients and served with steamed rice (''chaak''). Fried ones ({{lang|mni|kaanghou}}) are also favorites for many. ''Sebot'' is also eaten as a green vegetable.
====Other Asian cuisines====
In [[Sri Lanka]], it's called වැටකොළු (Waeṭakola, the [[Luffa acutangula]] variety) in [[Sinhalese language|Sinhalese]] and is a common ingredient in curries, even in dried forms.
In [[Vietnamese cuisine]], the [[gourd]] is called "''{{lang|vi|mướp hương}}''" and is a common ingredient in soups and stir-fried dishes.
In China and Taiwan (where it is called {{zh|s=丝瓜|zh|t=絲瓜|p=sīguā}}, or in English, "silk melon"), Indonesia (where it is called ''oyong''), and the Philippines (where it is called ''patola'' in [[Tagalog language|Tagalog]] and ''kabatiti'' in [[Ilokano language|Ilokano]]), in [[Timor-Leste]] it is also called "patola" or "batola" in [[Tetum language|Tetum]] and in Manipur, India, (where it is called {{lang|mni|sebot}}) the luffa is eaten as a green vegetable in various dishes.{{which|date=June 2018}}
In Japan it is called ''hechima'' ({{lang|ja|へちま}}) and is cultivated all over the country during summer. It is commonly used as a green vegetable in traditional dishes of the [[Ryukyu Islands]] (where it is called ''naabeeraa''). In other regions it is also grown for uses [[#Other uses|other than food]].
In Nepal it is called ''ghiraula'' and consumed as a vegetable at a young age. When it becomes ripe and dried, it is used as a body scrubbing material during bathing.
====Western cuisines====
Luffa is also known as "Chinese [[okra]]" in Canada and the U.S.
===Other uses===
In Japan, in regions other than the Ryukyu Islands and Kyushu, it is predominantly grown for use as a sponge or for applying soap, shampoo, and lotion. As with [[bitter melon]], many people grow it outside building windows as a natural sunscreen in summer.{{citation needed|date=December 2020}}
==Role in food chain==
Luffa species are used as food plants by the [[larva]]e of some [[Lepidoptera]] species, including ''[[Hypercompe albicornis]]'' and ''[[Zeugodacus tau]]''.<ref>{{Cite journal |last1=ZAELOR |first1=Jingyoh |last2=JULSIRIKUL |first2=Duangta |last3=KITTHAWEE |first3=Sangvorn |date=2021-01-17 |title=Genetic Diversity and Population Structure of ''Zeugodacus tau'' Walker (Diptera: Tephritidae) in Southern Thailand |journal=Walailak Journal of Science and Technology |volume=18 |issue=4 |doi=10.48048/wjst.2020.7291 |s2cid=234212403 |issn=2228-835X|doi-access=free }}</ref>
==Mechanical properties==
The luffa sponge is a [[Biology|biological]] cellular material. These materials often exhibit exceptional [[List of materials properties|mechanical properties]] at low [[Density|densities]]. While their mechanical performance tends to fall behind manmade materials, such as [[alloy]]s, [[ceramic]]s, [[plastic]]s, and [[Composite material|composites]], as a [[structural material]], they have long term [[sustainability]] for the natural environment. When compressed longitudinally, a luffa sponge is able to absorb comparable energy per unit mass as [[Metal foam|aluminum foam]].<ref>{{Cite journal|date=2012-11-01|title=Mechanical properties of luffa sponge|url=https://www.sciencedirect.com/science/article/abs/pii/S1751616112001993|journal=Journal of the Mechanical Behavior of Biomedical Materials|language=en|volume=15|pages=141–152|doi=10.1016/j.jmbbm.2012.07.004|issn=1751-6161|last1=Shen |first1=Jianhu |last2=Min Xie |first2=Yi |last3=Huang |first3=Xiaodong |last4=Zhou |first4=Shiwei |last5=Ruan |first5=Dong |pmid=23032434 }}</ref> Luffa sponges are composed of a complex network of [[fiber]] bundles connected to form a 3-dimensional, highly-[[Porosity|porous]] network.<ref name=":0">{{Cite journal|date=2014-04-11|title=A multiscale study on the structural and mechanical properties of the luffa sponge from Luffa cylindrica plant|url=https://www.sciencedirect.com/science/article/abs/pii/S0021929014001031|journal=Journal of Biomechanics|language=en|volume=47|issue=6|pages=1332–1339|doi=10.1016/j.jbiomech.2014.02.010|issn=0021-9290|last1=Chen |first1=Qiang |last2=Shi |first2=Quan |last3=Gorb |first3=Stanislav N. |last4=Li |first4=Zhiyong |pmid=24636532 }}</ref>
[[File:Luffa sponge diagram.jpg|thumb|Definition of the parts of a luffa sponge and the relevant coordinate system for mechanical properties measurements]]
The hierarchical structure of luffa sponges results in mechanical properties that vary with the component of sponge tested. Specifically, the mechanical properties of fiber bundles differ from those of blocks from the bulk of the sponge, which differ from those of the [[Cross section (geometry)|cross sections]] of the entire sponge.<ref name=":0" />
===Fiber-bundles===
[[Tensile testing|Uniaxial tensile tests]] of fiber bundles isolated from the inner surface provide insight this basic [[strut]] element of the luffa sponges. These fiber bundles vary in [[diameter]] from 0.3 to 0.5&nbsp;mm.<ref name=":0" /> Each fiber bundle has a low density core region not occupied by fibers.<ref name=":1">{{doi|10.3390/ma10050479 }}</ref> The [[Stress–strain curve|stress-strain]] response of the fiber bundles is nearly [[Linear elasticity|linear elastic]] all the way until [[fracture]], suggesting the absence of [[work hardening]]. The [[slope]] of the [[Linearity|linear]] region of the stress-strain curve, or [[Young's modulus|Young’s modulus]], is 236* MPa. The highest stress achieved before fracture, or [[ultimate tensile strength]], is 103 MPa. The strain at which failure occurs, or failure strain, is small at only 5%. The mechanical properties of fiber bundles decrease dramatically when the size of the hollow region inside the bundle increases.  Despite their low tensile strength, the fiber bundles have a high [[specific modulus]] of 2.07– 4.05 MPa⋅m<sup>3</sup>/kg, and their overall properties are improved when a high ratio of their cross sectional area is occupied by fibers, they are evenly distributed, and there is strong adhesion between fibers.<ref name=":0" /><ref name=":1" />
===Bulk-sponge===
[[File:Stress_strain_of_luffa_sponge.jpg|thumb|Characteristic stress-strain curve of a luffa sponge in compression]]
Block samples (height: 12.69 ± 2.35mm, width: 11.30 ± 2.88mm, length: 13.10 ± 2.64mm) cut from the core region and hoop region of the luffa sponge exhibit different mechanical behaviors under compression depending on both the orientation they are loaded in as well as the location in the sponge they are sampled from. The hoop region consists of the section of sponge located around the outside between the inner and outer surfaces, while the core region is from the sponge center. Samples from both the hoop and core regions exhibited [[Yield (engineering)|yielding]] when compressed in the longitudinal direction due to the [[buckling]] of fibers. With the highly aligned fibers from the inner surface removed from the hoop region block samples, this yield behavior disappears. In general, the inner surface fibers most significantly impact the longitudinal properties of the luffa sponge column followed by the [[Circumference|circumferential]] properties. There is no noticeable contribution to the [[Radius|radial]] properties. Additionally, the core region exhibits lower [[Yield (engineering)|yield stress]] and energy absorption (as determined by the area under the stress-strain curve) compared to the hoop region due to its greater [[porosity]].<ref name=":0" />
Overall, the stress-strain curves of block samples exhibit three stages of mechanical behavior common to porous materials. Namely, the samples follow [[linear elasticity]] for strains less than 10%, followed by a plateau for strains from 10% to 60%, and finally a stress increase associated with densification at strains greater than 60%. Segment samples created from cross sections of the entire luffa sponge (diameter: 92.51 ± 6.15mm, height: 19.76 ± 4.95mm) when tested in compression exhibit this same characteristic behavior.<ref name=":0" /> The three stages can be described by the equations:
# Linear elasticity region: <math>\sigma=E^*\varepsilon
</math> for <math>\varepsilon\le\varepsilon_e</math>
# Plateau region: <math>\sigma=\sigma_p^* </math> for <math>\varepsilon_e<\varepsilon\le\varepsilon_D(1-1/D)</math>
# Densification region: <math>\sigma=\sigma_p^*/D{(\varepsilon_D/\varepsilon_D-\varepsilon)}^m </math> for <math> \varepsilon>\varepsilon_D(1-1/D)</math> <ref name=":2">{{Cite journal|last=Gibson|first=Lorna J.|date=March 2005|title=Biomechanics of cellular solids|url=https://linkinghub.elsevier.com/retrieve/pii/S0021929004004919|journal=Journal of Biomechanics|language=en|volume=38|issue=3|pages=211–223|doi=10.1016/j.jbiomech.2004.09.027|pmid=15652536 }}</ref>
In the above equations, <math>E^*</math> is the [[Young's modulus]] and <math>\sigma_p^*</math> the [[Yield (engineering)|yield strength]] of the sponge material. These are chosen to best fit [[experimental data]]. The strain at the [[Yield (engineering)|elastic limit]], where the plateau region begins, is denoted as <math>\varepsilon_e</math>, while the strain at the onset of the densification region is <math>\varepsilon_D</math>.<ref name=":2" />
<math>\varepsilon_D=1-1.4(\rho^*/\rho_s)</math>
Here <math>\rho^*</math> is the density of the bulk sponge <math>\rho_s</math> is the density of its constituent, the fiber bundle. The constant D defines the strain at the onset of densification as well as the stress relationship in the densification region. It is determined by fitting experimental data.<ref name=":2" />
===Dynamic loading===
The mechanical properties of Luffa sponges change under different [[strain rate]]s. Specifically, energy adsorption, [[compressive stress]], and plateau stress (which is in the case of foam materials corresponds to the yield stress) are enhanced by increasing the strain rate.<ref name=":0" /><ref name=":3">{{Cite journal|date=2013-07-01|title=Behaviour of luffa sponge material under dynamic loading|url=https://www.sciencedirect.com/science/article/abs/pii/S0734743X13000110|journal=International Journal of Impact Engineering|language=en|volume=57|pages=17–26|doi=10.1016/j.ijimpeng.2013.01.004|issn=0734-743X|last1=Shen |first1=Jianhu |last2=Xie |first2=Yi Min |last3=Huang |first3=Xiaodong |last4=Zhou |first4=Shiwei |last5=Ruan |first5=Dong |bibcode=2013IJIE...57...17S }}</ref> One explanation for this is that the luffa fibers undergo more axial deformation when dynamically loaded (high strain rates) than when [[Quasistatic loading|quasi-statically]] loaded (low strain rates).<ref name=":3" />
==Gallery==
<gallery>
File:Leiden University Library - Seikei Zusetsu vol. 26, page 023 - 苦瓜 - Momordica charantia L. - 糸瓜 - Luffa cylindrica (L.), 1804.jpg | Luffa (right), illustration from the Japanese agricultural encyclopedia Seikei Zusetsu (1804)
File:Luffa cylindrica1.jpg | Habitus of the vine
File:Luffa plant.jpg | Luffa in a coconut tree
File:Ridge Gourd Southern India.jpg|Commonly known as Ridge Gourd from Southern India
File:Glands in probract that attract ants.jpg|Extrafloral nectar glands<ref>{{cite journal |last1=Chakravarty |first1=H. L. |title=Extrafloral Glands of Cucurbitaceæ |journal=Nature |date=October 1948 |volume=162 |issue=4119 |pages=576–577 |doi=10.1038/162576b0 |bibcode=1948Natur.162..576C |s2cid=4128826 }}</ref> in [[Luffa acutangula]] and [[Oecophylla smaragdina]] ants
File:பீர்க்கு இலை, சென்னை,ஜூன் 2020.jpg|Luffa leaf
File:Natural loofah luffa sponges on an organic farm in Israel.jpg | A bag of dried mature luffa fruits.
File:Luffa aegyptiaca MHNT.BOT.2011.3.94.jpg | ''Luffa aegyptiaca'', fruit and seeds - [[MHNT]]
File:Luffa operculata MHNT.BOT.2011.3.93.jpg | ''Luffa operculata'', fruit - MHNT
File:Luffa sponge.png | A luffa sponge whose coarse texture helps with [[exfoliation (cosmetology)|skin polishing]]
File:Spongegourd.jpg | ''[[Luffa aegyptiaca]]'' sponge section magnified 100 times
File:Luffa acutangula seeds.jpg | ''Luffa acutangula'' seeds. Each division of the ruler is 1&nbsp;mm. Seeds of ''Luffa aegyptiaca'' look similar.
File:Pollens of Luffa.jpg|Pollen grains of Luffa
File:Lufa flowers.jpg|Luffa flowers
File:Sponges made of sponge gourd.jpg|Sponges made of sponge gourd
</gallery>
==References==
{{Reflist}}
==External links==
{{Commons category}}
* [http://www.plantnames.unimelb.edu.au/Sorting/Luffa.html Multilingual taxonomic information] from the University of Melbourne
{{Taxonbar|from=Q232909}}
{{Authority control}}
[[Category:Cucurbitaceae genera]]
[[Category:Cucurbitoideae]]
[[Category:Fruit vegetables]]
[[Category:Taxa named by Philip Miller]]