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{{Short description|Genus of plant, Coco de Mer}}
{{Redirect2|Coco de mer|sea coconut|the lingerie brand|Sam Roddick|the fruit of the sugar palm|Borassus flabellifer}}{{Use dmy dates|cs1-dates=ly|date=July 2022}}
{{Speciesbox
|image = Female coco de mer growth.jpg
|image_caption = Habit, with fruit
|status = EN
|status_system = IUCN3.1
|status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Fleischer-Dogley, F. |author2=Huber, M.J. |author3=Ismail, S. |date=2011 |title=''Lodoicea maldivica'' |volume=2011 |page=e.T38602A10136618 |doi=10.2305/IUCN.UK.2011-2.RLTS.T38602A10136618.en |access-date=19 November 2021}}</ref>
|display_parents = 3
|genus = Lodoicea
|parent_authority = [[Philibert Commerson|Comm.]] ex [[Augustin Pyramus de Candolle|DC.]]
|species = maldivica
|authority = ([[Johann Friedrich Gmelin|J.F.Gmelin]]) [[Christian Hendrik Persoon|Persoon]]
|synonyms =
{{Collapsible list |
{{Plainlist | style = margin-left: 1em; text-indent: -1em; |
*''Borassus sonneratii'' <small>Giseke</small>
*''Cocos maldivica'' <small>J.F.Gmel.</small>
*''Cocos maritima'' <small>Comm. ex H.Wendl.</small>
*''Lodoicea callypige'' <small>Comm. ex J.St.Hil.</small>
*''Lodoicea sechellarum'' <small>Labill.</small>
*''Lodoicea sonneratii'' <small>(Giseke) [[Henri Ernest Baillon|Baill.]]</small>
}}
}}
|synonyms_ref = <ref>{{cite web|url=http://www.worldfloraonline.org/taxon/wfo-0000230541|title=''Lodoicea maldivica'' (J.F.Gmel.) Pers. |website=World Flora Online |date=2022 |publisher=The World Flora Online Consortium |access-date=22 June 2022 }}</ref><ref name="POWOsynonyms">{{cite web|url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:668084-1#synonyms |title=''Lodoicea maldivica'' (J.F.Gmel.) Pers., Syn. Pl. 2: 630 (1807). |date= 2022 |work= Plant of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=12 November 2022}}</ref>
}}
'''''Lodoicea''''',<ref name="POWOgenus">{{cite web|url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:31334-1#children |title=''Lodoicea'' Comm. ex DC., Bull. Sci. Soc. Philom. Paris 2: 171 (1800). |date= 2022 |work= Plant of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=12 November 2022 }}</ref> commonly known as the '''sea coconut''', '''coco de mer''', or '''double coconut''', is a [[monotypic taxon|monotypic]] genus in the [[Arecaceae|palm family]]. The sole species, '''''Lodoicea maldivica''''', is [[endemic (ecology)|endemic]] to the islands of [[Praslin]] and [[Curieuse]] in the [[Seychelles]]. It has the largest seed in the plant kingdom. It was also formerly found on the small islets of St Pierre, Chauve-Souris, and Ile Ronde (Round Island), all located near Praslin, but had become extinct there for a time until recently reintroduced.
==Taxonomy==
The name of the genus ''Lodoicea'' is given by [[Philibert Commerson]], it may be derived from ''Lodoicus'', a [[Latin]]ised form of ''Louis'' (typically ''[[Ludovicus]]''), in honour of King [[Louis XV of France]].<ref>{{cite book |last1=Wise |first1=Rosemary |date=1998 |title=A Fragile Eden: Portraits of the Endemic Flowering Plants of the Granitic Seychelles|url=https://books.google.com/books?id=tklXwuPQB0kC&pg=PT27 |language=en|publisher=Princeton University Press |isbn=978-0-691-04817-8 |page=Plate 27 }}</ref> Other sources say that ''Lodoicea'' is from [[Laodice (daughter of Priam)|Laodice]], the daughter of [[Priam]] and [[Hecuba]].<ref>{{cite book |last1=Craig |first1=John |title=A new universal etymological technological, and pronouncing dictionary of the English language |year=1859}}</ref>
''Lodoicea'' belongs to the [[Coryphoideae]] subfamily and tribe [[Borasseae]]. Borasseae is represented by four genera in [[Madagascar]] and one in Seychelles out of the seven worldwide. They are distributed on the coastlands surrounding the [[Indian Ocean]] and the existing islands within. ''[[Borassus]]'', the genus closest to ''Lodoicea'', has about five species in the "old world," one species in [[Africa]], one in [[India]], [[South-East Asia]] and [[Malaysia]], one in [[New Guinea]] and two species in Madagascar.<ref name=UD>{{Cite book |last1=Uhl |first1=Natalie |last2=Dransfield |first2=John|year=1987 |title=Genera Palmarum: A Classification of Palms Based on the Work of Harold E. Moore, Jr. |publisher=Allen Press |isbn=9780935868302}}</ref>
==Description==
[[Image:Cocodemerforest.jpg|right|thumb|The Vallée de Mai palm forest in Praslin]]
[[File:Lodoicea_seed.png|right|thumb|''Lodoicea maldivica'' seed from the Royal Ontario Museum's green plant herbarium.]]
The tree generally grows to 25–34 m (82–111.5&nbsp;ft) tall. The tallest on record, measured on the ground after felling, was {{convert|56.7|m|ft|abbr=on}} in total height.<ref>{{cite journal |date= 1866 |title= Letter from Swinburne Ward, Esq., to Sir William Hooker, F.R.S. |url= https://www.biodiversitylibrary.org/item/8360#page/266/mode/1up |journal= The Journal of the Linnean Society. Botany |volume= 9 |pages= 259–261 |via= Biodiversity Heritage Library |access-date=12 November 2022}}</ref>{{rp|260}} The [[leaf|leaves]] are fan-shaped, 7–10 m long and 4.5 m wide with a 4 m [[Petiole (botany)|petiole]] in mature plants. However juveniles produce much longer petioles; up to {{convert|9|m|ft|0|abbr=on}}<ref>Biotropica Vol. 15 # 1 (March 1983) p. 18 Fig 3</ref><ref>{{cite book |last=Corner |first= E.J.H. |author-link= E. J. H. Corner |date= 1966 |title= Natural History of Palms |url=https://books.google.com/books?id=7M09AAAAIAAJ |location=Berkeley, California |publisher= University of California Press |pages= 314–315 |isbn=}}</ref> or even {{convert|10|m|ft|abbr=on}}.<ref>{{cite journal |last1= Coativy |first1= Rene |date= Summer 2010 |title=<!-- Title cannot be found -->|journal=The Palm Journal |issue= 195 |page= 6 plus photo inside front cover p. 1}}</ref> It is [[plant sexuality|dioecious]], with separate male and female plants. The male [[flower]]s are arranged in a [[catkin]]-like [[inflorescence]] up to 2&nbsp;m (6.5&nbsp;ft) long<ref name=photomazza/> which continues to produce pollen over a ten-year period; one of the longest-living inflorescences known. The mature [[fruit]] is 40–50&nbsp;cm in diameter and weighs 15–30&nbsp;kg, and contains the largest [[seed]] in the [[plant]] [[kingdom (biology)|kingdom]].<ref name="Kew"/> The fruit, which requires 6–7 years to mature and a further two years to germinate, is sometimes also referred to as the '''sea coconut''', '''love nut''', '''double coconut''', '''coco fesse''', or '''Seychelles nut'''.<ref>{{cite news| url=http://news.bbc.co.uk/2/hi/programmes/from_our_own_correspondent/9538059.stm |publisher=[[BBC News]] |title=Royal honeymooners' 'erotic' souvenir |author=Tim Ecott |date=16 July 2011}}</ref>
While the functional characteristics of ''Lodoicea'' are similar to other trees of monodominant forests in the humid tropics, its unique features include a huge seed, effective funnelling mechanism and diverse community of closely associated animals. These attributes suggest a long evolutionary history under relatively stable conditions.<ref name="Edwards et al 2015">{{cite journal|last1=Edwards|first1=Peter J.|last2=Fleischer-Dogley|first2=Frauke|last3=Kaiser-Bunbury|first3=Christopher N. |year=2015 |title=The nutrient economy of ''Lodoicea maldivica'', a monodominant palm producing the world's largest seed|journal=New Phytologist |volume=206 |issue=3 |pages=990–999 |doi=10.1111/nph.13272 |pmid=25616088|doi-access=free}}</ref> Of the six monospecific endemic palms in Seychelles, ''Lodoicea'' is the "only true case of [[island gigantism]] among Seychelles flowering plants, a unique feature of Seychelles vegetation".<ref name="Proctor1984">{{cite book|last= Proctor|first= J.|editor-last= Stoddart|editor-first=D. R. |title= Biogeography and Ecology of the Seychelles Islands|url= https://books.google.com/books?id=XAZUuAAACAAJ|contribution= Vegetation of the granitic islands of the Seychelles|year= 1984|publisher=W. Junk|isbn= 978-90-6193-881-1|oclc= 906429733}}</ref> It holds eleven botanical records:
* It produces the largest wild fruit so far recorded, weighing up to 36&nbsp;kg (79.2&nbsp;lbs),<ref>{{cite journal |last=Hartman |first=Carl |date=November 2001 |title= ...and Around the World |journal=The Palm Journal |volume= |issue=161 |page=41}}</ref> and perhaps as much as 99 pounds (45 kilograms).<ref>{{cite journal | title=Observations on the Morphology, Pollination and Cultivation of Coco de Mer (''Lodoicea maldivica'' (J F Gmel.) Pers., Palmae) |journal=Journal of Botany |last= Blackmore | first= Stephen |display-authors=etal | date= 2012 | page= 1 |doi=10.1155/2012/687832 |doi-access=free |volume=2012}}</ref> (although domesticated [[pumpkin]]s and [[watermelon]]s can be much heavier)
* The fruit is composed of three [[carpel]]s which are the largest of any flowering plant (although the carpels of ''[[Entada]]'' spp. are longer).
* These fruit are the slowest to mature, requiring 8 to 10 years.<ref>{{cite journal | last= Clarke | first= George | date= February 1841 | title= Some Further Particulars of the Coco de Mer | journal= Annals and Magazine of Natural History | volume= 6 | issue= 39 | page=409}}</ref><ref>{{cite book | last= MacMillan | first= Hugh F. | date= 1943 | title= Tropical Planting and Gardening | location= London | publisher= MacMillan and Co. Ltd | page= 160 (Photo and caption)}}</ref>
* The mature seeds weighing up to 17.6&nbsp;kg (29&nbsp;lbs) are the world's heaviest<ref name="bbc" /><ref name="UD" /><ref name="Wise" />
* The seed upon germinating, produces the longest known [[cotyledon]], up to four meters (13&nbsp;feet).<ref>{{cite book |last=Corner |first=E.J.H. |date=1966 |title=Natural History of Palms |location=Berkeley, CA |publisher=Univ. of Calif. Press |page=194}}</ref> and on occasion as long as ten meters (33 feet).<ref name="BCS">{{cite book |last1=Beaver |first1=Katy |last2=Chong-Seng |first2=Lindsay |date=1992 |title=Vallee de Mai -Text and Photographs by Katy Beaver and Lindsay Chong-Seng |location= |publisher=Space Publishing |pages=1–60}}</ref>
* It is the slowest growing of all large trees,<ref>{{cite journal | date= Autumn 2004 | last1= Moore | first1= Randy | last2= Montes | first2= Dr. Felix | title= Gardens - Peradinaya Royal Botanic Gardens | journal= The Palm Journal | volume= <no volumes> | issue= 178 | page= 35 (text and photo)}}</ref> although some small to medium-sized desert trees are slower. At the [[Peradenaya Royal Botanic Gardens]], it grew an average of 1.29 inches (33 millimeters) per year over a period of 140 years.
* The female flowers are the largest of any palm, up to four inches (ten centimeters) in diameter.<ref name="UD" /><ref name="Wise" /><ref>{{cite journal | last= Bailey | first= Liberty Hyde | date= February 11, 1942 | title= Palms of the Seychelles | journal= Gentes Herbarium | volume= 6 | issue= 1 | page= 11}}</ref>
* The male catkins, up to two meters (6.5 feet) in length, are the longest known.<ref name=photomazza/>
* The [[sepal]]s, which grow with the fruit, are the largest known; up to 9 inches (23 centimeters) long by six inches (15 centimeters) wide.<ref>{{cite journal | last=Yates | first= Maya | date= June 1971 | title= The Seychelles - Treasure Islands of Indian Ocean | journal= Venture - the Traveler's World | volume= 8 | issue= 5 | pages= 41 et seq }}</ref>
* The leaves of ''Lodoicea'' have the longest lifespan of any [[monocot]], nine years to develop in the terminal spike, and then nine more years as a fully functioning leaf.<ref>{{cite book | last= Corner | first= Prof. E.J.H. | date= 1966 | title= Natural History of Palms | location= Berkeley, Calif. | publisher= Univ. Calif. Press | pages= 45–49 }}</ref> However, adult ''Lodoicea'' can have as many as twenty leaves with a potential lifespan of 24 years.<ref>{{cite journal | last1= Savage | first1= Andrew J.P. | last2= Ashton | first2= Peter S | date= March 1983 | title= The Population Structure of the Double Coconut...etc.| journal= Biotropica | volume= 15 | issue= 1 | page= 1 | doi= 10.2307/2387992 | jstor= 2387992 }}</ref>
* Finally, ''Lodoicea'' is the most efficient plant known at recovering nutrients from moribund leaves.<ref>{{Cite web|author=Colin Barras |date=2015-02-06 |title=The secret of the world's largest seed revealed |website=Newscientist |url=https://www.newscientist.com/article/dn26930-the-secret-of-the-worlds-largest-seed-revealed/ |url-access=registration |access-date=2022-07-09}}</ref><ref>Science News (May 16, 2015) p.5.{{full citation needed|date=July 2022}}</ref>
Of the six endemic palms in Seychelles, it is the only [[dioecy|dioecious]] species, with male and female flowers on different plants.<ref name=EKF>Edwards, Kollmann & Fleischmann's selective review of the biology of the species (2002)</ref>
===Habit===
''L. maldivica'' is robust, solitary, up to 30 m tall with an erect, spineless, stem which is ringed with leaf scars (Calstrom, unpublished). The base of the trunk is of a bulbous form and this bulb fits into a natural bowl, or socket, about {{convert|2+1/2|ft|cm|order=flip|round=5|abbr=on}} in diameter and {{convert|18|in|cm|order=flip|abbr=on}} in depth, narrowing towards the bottom. This bowl is pierced with hundreds of small oval holes about the size of a thimble with hollow tubes corresponding on the outside through which the roots penetrate the ground on all sides, never, however, becoming attached to the bowl; they are partially elastic, affording an almost imperceptible but very necessary "play" to the parent stem when struggling against the force of violent gales.
===Leaves===
The crown is a rather dense head of foliage with leaves that are stiff, palmate up to 10 m in diameter and petioles of two to four metres in length. The leaf is plicate at the base, cut one third or more into segments 4–10&nbsp;cm broad with bifid end which are often drooping. A triangular cleft develops at the petiole base.<ref name=UD/> The palm leaves form a huge funnel that intercepts particulate material, especially pollen, which is flushed to the base of the trunk when it rains. In this way, ''L. maldivica'' improves its nutrient supply and that of its dispersal-limited offspring.<ref name="Edwards et al 2015" />
===Flowers===
[[File:KokoDeMer2016.png|thumb|left|Two endemic species on a coco de mer in Vallée de Mai (March 2016)]]
The clusters of staminate flowers are arranged spirally and are flanked by very tough leathery bracts. Each has a small bracteole, three sepals forming a cylindrical tube, and a three-lobed corolla. There are 17 to 22 stamens. The pistillate flowers are solitary and borne at the angles of the rachis and are partially sunken in it in the form of a cup. They are ovoid with three petals as well as three sepals.<ref name="UD" /> It has been suggested that they may be pollinated by animals such as the endemic lizards that inhabit the forest where they occur.<ref name="BCS"/> Pollination by wind and rain are also thought to be important.<ref name="EKF" /> Only when ''L. maldivica'' begins to produce flowers, which can vary from 11 years to 45 or more, is it possible to visually determine the sex of the plant. The nectar and pollen are also food for several endemic animals e.g. [[Phelsuma grandis|bright green geckos (''Phelsuma'' sp.)]], white slugs (''[[Vaginula]] seychellensis'') and insects.<ref>{{Cite web |title=Vaginula seychellensis |website=www.safari-afrika.de |url=http://www.safari-afrika.de/html/vaginula_seychellensis.html |access-date=2016-04-04 |archive-date=2016-04-14  |archive-url=https://web.archive.org/web/20160414102848/http://www.safari-afrika.de/html/vaginula_seychellensis.html |url-status=dead }}</ref>
===Inflorescence===
[[Image:CocoMale.jpg|right|thumb|Male inflorescence]]
[[Inflorescence]]s are inter[[foliar]], lacking a covering [[spathe]] and shorter than the leaves. The [[staminate]] inflorescence is catkin-like, one to two metres long by about three inches (8 centimeters) in width and produces pollen over a period of 8 to ten years.<ref>{{cite journal | last= Clark Esq. | first= George | date= February 1841 | title= Some Further Peculiarities of the Coco-de-Mer |journal= The Annals and Magazine of Natural History | volume= 6 | issue= 39 | page= 115}}</ref> These catkins are generally terminal and solitary, but sometimes two or three catkins may be present. The pistillate inflorescences are also one to two metres long, unbranched, and the flowers are borne on a zig-zagging [[Rachilla (floral axis)|rachilla]].<ref name=Wise/>
===Fruit===
[[Image:Lodoicea Maldivica B.jpg|left|thumb|Fruit]]
[[File:Coco de mer - BOT.2007.26.21.jpg|right|thumb|Nut (with outer husk removed), with affixed label designating its origin]]
The fruit is bilobed, flattened, 40 to 50&nbsp;cm long ovoid and pointed, and contains usually one but occasionally two to four seeds. The [[epicarp]] is smooth and the [[mesocarp]] is fibrous. The [[endosperm]] is thick, relatively hard, hollow and homogenous. The embryo sits in the sinus between the two lobes. During germination, a tubular [[cotyledon]]ary [[Petiole (botany)|petiole]] develops that connects the young plant to the seed. The length of the tube is reported to reach about four metres.<ref name=UD/> In the [[Vallée de Mai]], the tube may be up to 10 m long.<ref name=photomazza/><ref name=BCS/>
''L. maldivica'' was once believed to be a sea-bean or drift seed, a seed evolved to be dispersed by the sea. However, it is now known that the viable nut is too dense to float, and only rotted out nuts can be found on the sea surface,<ref>{{cite book |last= Gollner|first= Adam Leith |year= 1999 |title= The Fruit Hunters, a story of nature, adventure, commerce and obsession |publisher= Scribner |page= 114|isbn=978-0-7432-9694-6 }}</ref> thus explaining why the trees are limited in range to just two islands.
==Habitat==
''Lodoicea maldivica'' inhabits rainforests where there are deep, well-drained soils<ref name="Wise">{{cite book|last=Wise|first=R.|title=A Fragile Eden|year=1998|publisher=Princeton University Press|location=New Jersey}}</ref> and open exposed slopes; although growth is reduced on such eroded soils.<ref>{{ARKive|coco-de-mer|lodoicea-maldivica}}</ref>
== Phylogeny ==
Despite the Seychelles’ proximity to Africa, the broader diversity of palm life on the islands are considered to be slightly closer phylogenetically to that of south Asia;<ref name="Proctor1984" /> with members of the palm subtribe Oncospermatinae occurring both in the Seychelles group and in the Mascarene Islands, Sri Lanka, Borneo, the Malay Peninsula, and the Philippines.<ref name=":0">{{Cite journal |last1=Bellot |first1=Sidonie |last2=Bayton |first2=Ross P. |last3=Couvreur |first3=Thomas L. P. |last4=Dodsworth |first4=Steven |last5=Eiserhardt |first5=Wolf L. |last6=Guignard |first6=Maïté S. |last7=Pritchard |first7=Hugh W. |last8=Roberts |first8=Lucy |last9=Toorop |first9=Peter E. |last10=Baker |first10=William J. |date=November 2020 |title=On the origin of giant seeds: the macroevolution of the double coconut ( Lodoicea maldivica ) and its relatives (Borasseae, Arecaceae) |journal=New Phytologist |language=en |volume=228 |issue=3 |pages=1134–1148 |doi=10.1111/nph.16750 |issn=0028-646X |pmc=7590125 |pmid=32544251}}</ref> A genetic sequencing study of the Lodoicea and its palm showed similarity between south Asiatic palms and Lodoicea. Lodoicea are one of four genera in the [[Lataniieae]] subtribe of the Borrassae tribe, and sequencing found them to be to be very closely related to the Borassus and Borassodendron genera (although notably the phylogenetic placement of Lodoicea was among the least confident).<ref name=":0" /> The Borassus and Borassodendron genera together include species in Southeast Asia, Malaysia, India, New Guinea, and Madagascar;<ref name=":1">{{Cite book |last=Fischer |first=Angelika |title=Coco de mer: Myth and Eros of the Sea Coconut |publisher=Edition A.B. Fischer |year=2008 |isbn=9783937434223}}</ref> thus this study provided genetic evidence for the suspected close relationships between Lodoicea and south Asian palms.
== Dispersal ==
Genetic similarity between Lodoicea and south-asian palms despite their geographical distance raises questions about ancestral Lodoicea’s historical dispersal to the Seychelles; and this natural history of Lodoicea is further obscured by the geology of the Seychelles, as the entirety of the archipelago (excluding certain Pleistocene and coral reef formations) is composed of non-fossiliferous rock.<ref name="Proctor1984" /> As such, the prehistoric origins of Seychelles flora is inferred using circumstantial geological and botanical evidence.<ref name="Proctor1984" />
=== Geologic Drift-Dispersal Hypothesis ===
Coco de Mer’s ancestral dispersal to the Seychelles may have occurred as Tertiary palm relatives native to Gondwonaland rode the Indian subcontinent during its northward continental drift, whereupon populations were deposited on the modern day Seychelles. This hypothesis derives from the geologic formation of the Seychelles themselves, and offers a strong explanation of Lodoicea’s modern day close relation to Asiatic palms. The granite which forms the majority of the Seychelles archipelago was formed within the Indian subcontinent, and was deposited in its modern day location in the Indian ocean following the detachment and northern drift of the subcontinent from Gondwana, before colliding with modern day south-Asia ~50 mya.<ref>{{Cite journal |last1=Baker |first1=B. H. |last2=Miller |first2=J. A. |date=July 1963 |title=Geology and Geochronology of the Seychelles Islands and Structure of the Floor of the Arabian Sea |url=https://www.nature.com/articles/199346a0 |journal=Nature |language=en |volume=199 |issue=4891 |pages=346–348 |doi=10.1038/199346a0 |bibcode=1963Natur.199..346B |s2cid=4197326 |issn=0028-0836}}</ref> Divergence between the palm populations would then follow from the isolation of the archipelago from the rest of Gondwonaland. Evidence suggests at least a proportion of the diversity of Flora on the islands are of “very ancient origin”,<ref name="Proctor1984" /> perhaps being evidence of the persistence of some aboriginal Indian subcontinental species, of which the ancestors to the Lodoicea may have been a member. The plausibility of this hypothesis is dependent on whether the Seychelles remained at least in part above sea-level for the duration of their formation, as a complete inundation with sea water at any point during the formation of the islands would have killed any aboriginal flora. Whether such an inundation ever occurred during the formation of the Seychelles is unknown.<ref name="Proctor1984" />
=== Oceanic Dispersal Hypothesis ===
A 2020 genetic-sequencing study of palm species found genetic evidence for an oceanic dispersal of the ancestors to modern [[Lataniieae]] palms, from south Asia to the Mascarene and Seychelle islands. Though modern viable Coco de Mer fruits are too heavy to float and thus would be unable to disperse oceanically, genetic evidence suggests that ancestors to Lataniieae palms underwent evolutionary periods of relatively rapid increases in seed size, with the Lodoicea serving as the most extreme example. Thus, Lodoicea ancestors may have possessed small-enough seeds for oceanic dispersal to be viable,<ref name=":0" /> with an evolutionary increase in seed size occurring in the Seychelles after Lodoicea’s ancestral dispersal. Furthermore, it is likely that at certain points during the geologic formation of the Seychelles, the oceanic gaps between landmasses were much smaller, making oceanic dispersal more viable still.<ref name="Proctor1984" /> As such, a combination of the two hypotheses, wherein ancestral palms native to the Indian subcontinent rode the subcontinent during continental drift, and then dispersed oceanically to the Seychelles after their formation, but while the rest of the Indian subcontinent was relatively nearby.
== Evolution of the coco de mer fruit’s size ==
Despite their relative recency of this divergence from the common ancestor shared with other palms, Lodoicea are unique across a variety of traits. Though Lodoicea is not the only palm in its tribe that produces very large fruits, the syncarpous clade of palms exhibit wide variation in seed sizes, ranging from the seeds of the Caryoteae palms of only several millimeters, to the seeds of Borasseae which are often several centimeters in length (The Lodoicea is the most extreme example of this group).<ref name=":0" /> For this reason, the ecological and genetic factors explaining the large size of Lodoicea’s fruit to such an extreme are of particular interest to evolutionary biologists. The divergence of size in Lodoicea’s fruit subsequent to its isolation from ancestors has been cited as an example of island gigantism,<ref name=":1" /> which describes the tendency for traits or organisms to increase in size over evolutionary time subsequent to isolation from a primary population on an island (see also [[Insular biogeography|island biogeography]]). One hypothesis for the ecological driver of the development of Lodoicea’s large seed is the historic lack of ground dwelling mammalian predators on the Seychelles, allowing for large fruits on the ground to avoid predation for long enough for their large energy stores to be effectively utilized by growing offspring.<ref name=":2">{{Cite journal |last1=Edwards |first1=Peter J. |last2=Kollmann |first2=Johannes |last3=Fleischmann |first3=Karl |date=June 2002 |title=Life history evolution in Lodoicea maldivica (Arecaceae) |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1756-1051.2002.tb01371.x |journal=Nordic Journal of Botany |language=en |volume=22 |issue=2 |pages=227–238 |doi=10.1111/j.1756-1051.2002.tb01371.x |issn=0107-055X}}</ref> Agricultural surveys of the Seychelles tend to categorize the islands as having very shallow, nutrient-poor soils,<ref>{{Cite journal |last=Kueffer |first=Christoph |date=January 2010 |title=Reduced risk for positive soil-feedback on seedling regeneration by invasive trees on a very nutrient-poor soil in Seychelles |url=http://link.springer.com/10.1007/s10530-009-9433-4 |journal=Biological Invasions |language=en |volume=12 |issue=1 |pages=97–102 |doi=10.1007/s10530-009-9433-4 |bibcode=2010BiInv..12...97K |hdl=20.500.11850/17444 |s2cid=33017625 |issn=1387-3547|hdl-access=free }}</ref> and the life-cycle of the coco de mer often involves a very long period of subterranean transversal of the primary apical shoot after fertilization and excision from the parent tree, wherein the growing plant cannot use solar radiation to undergo photosynthesis {{citation needed|date=March 2024}}. These facts may jointly act as evolutionary incentives for the development of large, nutrient rich fruits, to feed the growing plant and increase likelihood of successful reproduction.
Competition may also be the driving factor in the evolution of the size of Lodoicea’s fruit. One hypothesis asserts that competition between parent tree and its progeny, as well as competition between sibling offspring, drove the large size of the Coco de Mer’s fruit. The hypothesis suggests that because Coco de Mer fruits fall directly at the base of their parental tree, there is strong competition between parent and offspring for resources, within which the already-established parent tree has a large asymmetric advantage. Furthermore, as the number of offspring produced by a specific parent increases, the number of individuals growing its immediate surroundings increases, and thus the competition for resources between its offspring worsens. Therefore, there exists a selective pressure favoring the production of fewer offspring, each with a maximal chance of successfully reaching adulthood conferred by large energy reserves in the fruit.<ref name=":2" /> A related hypothesis states that low light availability in the rainforest understory favored juveniles which could quickly produce tall and wide initial leaves, to maximize photosynthetic area as quickly as possible; which would be made possible by a large, nutrient-rich seed. This is perhaps corroborated by the Coco de Mer’s noted ability to quickly produce a very large first stem and leaf,<ref name=":2" /> perhaps suggesting that fast and robust initial growth is indeed heavily selected towards. It is also noteworthy that many of the hypotheses presented to explain the size of Lodoicea’s fruit are not mutually exclusive, and could act jointly.
==History and mythology==
{{Main article|Legends of the coco de mer}}
The species was formerly known as the '''Maldive coconut'''. Its scientific name, ''Lodoicea maldivica'', originated before the 18th century when the [[Seychelles]] were uninhabited. In centuries past, the fruits that fell from the trees and ended up in the sea would be carried away eastwards by the prevailing sea currents. The nuts can only float after the germination process, when they are hollow. In this way many drifted to the [[Maldives]] where they were gathered from the beaches and valued as an important trade and medicinal item.<ref name=bbc>{{cite news|last=Ecott|first=Tim|title=Royal honeymooners' 'erotic' Seychelles souvenir|url=http://news.bbc.co.uk/1/hi/programmes/from_our_own_correspondent/9538059.stm|access-date=17 July 2011|newspaper=BBC News|date=16 July 2011}}</ref><ref>{{cite book |last=Romero-Frias |first= Xavier |author-link= Xavier Romero-Frias |date= 1999 |title= The Maldive Islanders, A Study of the Popular Culture of an Ancient Ocean Kingdom |location= Barcelona |isbn=84-7254-801-5 }}</ref>
Until the true source of the nut was discovered in 1768 by [[Marc-Joseph Marion Dufresne|Dufresne]], it was believed by many to grow on a mythical tree at the bottom of the sea. European nobles in the sixteenth century would often have the shells of these nuts polished and decorated with valuable jewels as collectibles for their private galleries. The coco de mer tree is now a rare and protected species.
==Uses==
[[Image:Lodoicea Maldivica A.jpg|right|thumb|Tree in a Sri Lanka botanic garden]]
The species is grown as an [[ornamental tree]] in many areas in the tropics (including, for example, botanical gardens in [[Sri Lanka]] and [[Thailand]]), and subsidiary populations have been established on [[Mahé, Seychelles|Mahé]] and [[Silhouette Island]]s in the Seychelles to help conserve the species. The fruit is used in [[Siddha medicine]], [[Ayurvedic medicine]] and also in [[traditional Chinese medicine]]. In traditional Chinese medicine, it is used to treat [[inflammation]], [[nausea]] and [[abdominal pain]].<ref>{{Cite web |date=2020-12-02 |title=What is Asian Sea Coconut? |url=https://asianinspirations.com.au/food-knowledge/what-is-asian-sea-coconut/ |access-date=2022-01-11 |website=Asian Inspirations}}</ref> In food, it is typically found as flavor enhancers for soups in southern Chinese cuisine, such as that of [[Guangdong Province]].{{citation needed|date=May 2021}}
The seeds of ''Lodoicea'' have been highly prized over the centuries; their rarity caused great interest and high prices in royal courts, and the tough outer seed coat has been used to make bowls such as for Sufi/Dervish beggar-alms ''[[kashkul]]'' bowls and other instruments.<ref name="Wise"/>
==Threats==
''Lodoicea maldivica'' is officially classified as an [[endangered species]] by the [[International Union for Conservation of Nature]] (IUCN), with only approximately 8,000 wild mature trees left as of 2019.<ref name="Kew">{{Cite web|last=Bellot|first=Sidonie|date=8 July 2020|title=Double coconut: The largest seed in the world|url=https://www.kew.org/read-and-watch/double-coconut-largest-seed-in-the-world|access-date=25 July 2021|website=Kew Gardens}}</ref> The history of exploitation continues today, and the collection of nuts has virtually stopped all natural regeneration of populations<ref name="srdb">{{cite book|last=Gerlach |first=J.|title=Seychelles Red Data Book|year=1997 |publisher=The Nature Protection Trust of the Seychelles |location=Seychelles}}</ref> with the exception of the introduced population on Silhouette. This palm has been lost from the wild from three Seychelles islands within its former range.<ref name="srdb"/> Habitat loss is one of the major threats to the survival of remaining populations, there have been numerous fires on the islands of Praslin and Curieuse, and only immature trees remain over large parts of these islands.<ref name="srdb"/>
==Conservation==
The Seychelles is a [[World Heritage Site]], and a third of the area is now protected.<ref>{{cite book|title=Seychelles: Jewel of a Lost Continent|series=Natural World|date=10 December 2000|publisher=BBC}}</ref> The main populations of ''Lodoicea maldivica'' are found within the Praslin and Curieuse National Parks,<ref name="srdb"/> and the trade in nuts is controlled by the Coco-de-mer (Management) Decree of 1995.<ref name="srdb"/> Firebreaks also exist at key sites in an effort to prevent devastating fires from sweeping through populations.<ref name="srdb"/> Cultivated palms are grown on a number of other islands and are widely present in botanic gardens; although the collection of seeds in order to recruit these populations may be a further threat to the remaining natural stands.<ref name="srdb"/> Conservation priorities are the continued protection of populations, enforcement of regulations and effective fire control.<ref name="srdb"/>
A single cultivated plant at the Botanical Garden of [[Kolkata]], maintained by the [[Botanical Survey of India]], was successfully artificially pollinated in 2015.<ref>{{cite news|url=http://www.thehindu.com/news/national/indias-only-double-coconut-tree-artificially-pollinated/article7310257.ece|title=India's only double coconut tree artificially pollinated|author=Shiv Sahay Singh|newspaper=The Hindu|date=13 June 2015}}</ref>
==Gallery==
<gallery>
File:Keskul GrantBowl.JPG|Sufi [[kashkul]]s were often made from a coco de mer which would be difficult to find for ordinary beggars.
File:Kashkul, or Beggar’s Bowl, with Portrait of Dervishes and a Mounted Falconer, A.H. 1280.jpg|Kashkul with portrait of dervishes and a mounted falconer, A.H. 1280. [[Brooklyn Museum]].
</gallery>
==References==
{{ARKive attribute}}
{{Reflist|2|refs=
<ref name=photomazza>{{cite web |url=http://www.photomazza.com/?The-incredible-Maldivian-Lodoicea |title=The incredible Maldivian Lodoicea and the Vallee de Mai |last=Mazza |first=Giuseppe |translator=Mario Beltramini |access-date= September 29, 2015|archive-date=2016-05-05 |archive-url=https://web.archive.org/web/20160505180734/http://www.photomazza.com/?The-incredible-Maldivian-Lodoicea}}</ref>
}}
==Further reading==
*[https://web.archive.org/web/20110725013950/http://www.arkive.org/coco-de-mer/lodoicea-maldivica/ Arkive: ''Lodoicea maldivica'']
*Palm Society of Australia: ''Lodoicea maldivica'' [http://www.pacsoa.org.au/palms/Lodoicea/maldivica.html description] and [http://www.pacsoa.org.au/palms/Lodoicea/maldivica1.html photo gallery]
* Hutchinson, 1959, ''The Families of Flowering Plants'' (2nd ed.)
* Fleischer-Dogley, F. (2006). ''Towards sustainable management of Lodoicea maldivica (Gmelin) Persoon,'' PhD thesis, University of Reading, UK.
==External links==
{{Commons category|Lodoicea maldivica}}
*{{ARKive}}
{{Arecaceae genera}}
{{Taxonbar|from1=Q12237559|from2=Q732371}}
{{Authority control}}
[[Category:Fruits originating in Africa]]
[[Category:Taxa named by Philibert Commerson]]
[[Category:Coryphoideae]]
[[Category:Trees of Seychelles]]
[[Category:Endemic flora of Seychelles]]
[[Category:Endangered plants]]
[[Category:Decorative fruits and seeds]]
[[Category:Monotypic Arecaceae genera]]
[[Category:Dioecious plants]]