View source for Pandanus tectorius

{{Short description|Species of plant}}
{{Redirect|Ketaki|the Indian tree also known as ketaki|Pandanus odorifer}}
{{Speciesbox
| image = Pandanus tectorius.jpg
| image_caption = Growing in the mountains of [[Oahu|O{{okina}}ahu]], [[Hawaii]]
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Thomson, L. |author2=Thaman, R. |author3=Guarino, L. |author4=Taylor, M. |author5=Elevitch, C. |date=2019 |title=''Pandanus tectorius'' |volume=2019 |page=e.T62335A135987404 |doi=10.2305/IUCN.UK.2019-3.RLTS.T62335A135987404.en |access-date=19 November 2021}}</ref>
| genus = Pandanus
| species = tectorius
| authority = [[Sydney Parkinson|Parkinson]]<ref name="POWO">{{cite web |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:895770-1 |title=''Pandanus tectorius'' Parkinson |website=[[Plants of the World Online]] |publisher=Board of Trustees of the Royal Botanic Gardens, Kew |year=2025 |access-date=17 June 2025}}</ref>
|synonyms_ref = {{R|POWO}}
|synonyms =
{{Species list |header=332 synonyms |hidden=yes
|Corypha laevis|(Lour.) A.Chev.
|Pandanus absonus|H.St.John
|Pandanus adscendens|H.St.John
|Pandanus aequor|H.St.John
|Pandanus aitutakiensis|H.St.John
|Pandanus akiakiensis|H.St.John
|Pandanus ala-kai|Martelli
|Pandanus amplexus|H.St.John
|Pandanus angulosus|H.St.John
|Pandanus anisos|H.St.John
|Pandanus aoraiensis|H.St.John
|Pandanus apionops|H.St.John
|Pandanus asauensis|H.St.John
|Pandanus ater|H.St.John
|Pandanus baptistii|Misonne
|Pandanus bassus|H.St.John
|Pandanus bathys|H.St.John
|Pandanus benignus|H.St.John
|Pandanus bergmanii|F.Br.
|Pandanus bicurvatus|H.St.John
|Pandanus blakei|H.St.John
|Pandanus boraboraensis|H.St.John
|Pandanus bothreus|H.St.John
|Pandanus bowenensis|H.St.John
|Pandanus brachypodus|Kaneh.
|Pandanus brownii|H.St.John
|Pandanus bullii|Warb.
|Pandanus cacuminatus|H.St.John
|Pandanus calostigma f. samoanus|Martelli
|Pandanus carolinensis|Martelli
|Pandanus chamissonis|Gaudich.
|Pandanus charancanus|Kaneh.
|Pandanus christophersenii|H.St.John
|Pandanus collatus|H.St.John
|Pandanus complanatus|H.St.John
|Pandanus cooperi|(Martelli) H.St.John
|Pandanus coronatus|Martelli
|Pandanus coronatus f. minor|Martelli
|Pandanus crassiaculeatus|H.St.John
|Pandanus crassus|H.St.John
|Pandanus crustatus|Martelli
|Pandanus crustatus f. minor|Martelli
|Pandanus cylindricus|Kaneh.
|Pandanus cylindricus var. sinnau|Kaneh.
|Pandanus cymatilis|H.St.John
|Pandanus decorus|K.Koch
|Pandanus dhaenei|Pynaert
|Pandanus dicheres|H.St.John
|Pandanus dilatatus|Kaneh.
|Pandanus discolor|T.Moore & Mast.
|Pandanus distinctus|Martelli
|Pandanus divaricatus|H.St.John
|Pandanus divergens|Kaneh.
|Pandanus dotyi|H.St.John
|Pandanus douglasii|Gaudich.
|Pandanus drakei|H.St.John
|Pandanus drolletianus|Martelli
|Pandanus duriocarpoides|Kaneh.
|Pandanus duriocarpus|Martelli
|Pandanus edwinii|H.St.John
|Pandanus elevatus|H.St.John
|Pandanus enchabiensis|Kaneh.
|Pandanus erythrophloeus|Kaneh.
|Pandanus evexus|H.St.John
|Pandanus exilis|H.St.John
|Pandanus exilis var. juddii|H.St.John
|Pandanus extralittoralis|H.St.John
|Pandanus eyesyes|Kaneh.
|Pandanus fahina|H.St.John
|Pandanus faramaa|H.St.John
|Pandanus fatuhivaensis|H.St.John
|Pandanus fatyanion|(Kaneh.) Hosok.
|Pandanus ferulifer|H.St.John
|Pandanus filiciatilis|H.St.John
|Pandanus fischerianus|Martelli
|Pandanus fischerianus f. bergmanii|(F.Br.) B.C.Stone
|Pandanus fischerianus var. bryanii|B.C.Stone
|Pandanus fischerianus f. bryanii|B.C.Stone
|Pandanus fischerianus f. compressus|B.C.Stone
|Pandanus fischerianus var. cooperi|(Martelli) B.C.Stone
|Pandanus fischerianus var. rockii|(Martelli) B.C.Stone
|Pandanus flintinsularis|H.St.John
|Pandanus fragrans|Gaudich.
|Pandanus fragrans f. koidzumii|(Hosok.) B.C.Stone
|Pandanus fragrans f. marianus|B.C.Stone
|Pandanus fragrans f. megastigma|B.C.Stone
|Pandanus fragrans f. rotensis|(Hosok.) B.C.Stone
|Pandanus fragrans f. savannarum|B.C.Stone
|Pandanus fragrans f. tinianensis|B.C.Stone
|Pandanus futunaensis|H.St.John
|Pandanus gambierensis|H.St.John
|Pandanus glomerosus|H.St.John
|Pandanus grantii|H.St.John
|Pandanus guamensis|Martelli
|Pandanus haapaiensis|H.St.John
|Pandanus hendersonensis|H.St.John
|Pandanus heronensis|H.St.John
|Pandanus hivaoaensis|H.St.John
|Pandanus horneinsularum|H.St.John
|Pandanus hosinoi|Kaneh.
|Pandanus hosokawae|Kaneh.
|Pandanus houmaensis|H.St.John
|Pandanus hubbardii|H.St.John
|Pandanus humericus|H.St.John
|Pandanus inarmatus|H.St.John
|Pandanus inermis|Roxb.
|Pandanus inflexus|H.St.John
|Pandanus infundibuliformis|H.St.John
|Pandanus insularis|Kaneh.
|Pandanus interior|H.St.John
|Pandanus intralaevis|H.St.John
|Pandanus jaluitensis|Kaneh.
|Pandanus javanicus|K.Koch
|Pandanus javanicus variegatus|E.J.Lowe & W.Howard
|Pandanus jonesii|(F.Br.) H.St.John
|Pandanus kafu|Martelli
|Pandanus kamptos|H.St.John
|Pandanus katensis|F.Br.
|Pandanus koidzumii|Hosok.
|Pandanus korrensis|Kaneh.
|Pandanus kraussii|H.St.John
|Pandanus kusaiensis|Kaneh.
|Pandanus laculatus|H.St.John
|Pandanus laevis|Kunth
|Pandanus laevis|Lour.
|Pandanus lakatwa|Kaneh.
|Pandanus lambasaensis|H.St.John
|Pandanus laticanaliculatus|Kaneh.
|Pandanus laticanaliculatus var. edulis|Kaneh.
|Pandanus latior|H.St.John
|Pandanus lauensis|H.St.John
|Pandanus lennei|Pynaert
|Pandanus licinus|H.St.John
|Pandanus limitaris|H.St.John
|Pandanus littoralis|Jungh.
|Pandanus longifolius|H.L.Wendl.
|Pandanus macfarlanei|Martelli
|Pandanus macrocephalus|Kaneh.
|Pandanus makateaensis|H.St.John
|Pandanus malatensis|Blanco
|Pandanus mangarevaensis|H.St.John
|Pandanus mariaensis|H.St.John
|Pandanus marquesasensis|H.St.John
|Pandanus matukuensis|H.St.John
|Pandanus mbalawa|H.St.John
|Pandanus meetiaensis|H.St.John
|Pandanus mei|F.Br.
|Pandanus mendanensis|Martelli
|Pandanus menne|Kaneh.
|Pandanus menziesii|Gaudich.
|Pandanus metius|H.St.John
|Pandanus minysocephalus|H.St.John
|Pandanus montaguei|H.St.John
|Pandanus mooreaensis|H.St.John
|Pandanus moschatus|Miq.
|Pandanus moschatus|Rumph. ex Voigt
|Pandanus motuensis|H.St.John
|Pandanus nandiensis|H.St.John
|Pandanus navigatorum|Martelli
|Pandanus navigatorum var. elbertii|B.C.Stone
|Pandanus niueensis|H.St.John
|Pandanus notialis|H.St.John
|Pandanus oblatiapicalis|H.St.John
|Pandanus oblaticonvexus|H.St.John
|Pandanus obliquus|Kaneh.
|Pandanus odontoides|Hosok.
|Pandanus odoratissimus var. laevigatus|Martelli
|Pandanus odoratissimus var. laevis|(Warb.) Martelli
|Pandanus odoratissimus f. major|Martelli
|Pandanus odoratissimus var. oahuensis|Martelli
|Pandanus odoratissimus var. parksii|Martelli
|Pandanus odoratissimus var. pyriformis|Martelli
|Pandanus odoratissimus var. savaiensis|(Martelli) Martelli
|Pandanus odoratissimus var. setchellii|Martelli
|Pandanus odoratissimus var. spurius|Willd.
|Pandanus odoratissimus var. suvaensis|Martelli
|Pandanus okamotoi|Kaneh.
|Pandanus onoilauensis|H.St.John
|Pandanus orarius|H.St.John
|Pandanus otemanuensis|H.St.John
|Pandanus ovalauensis|H.St.John
|Pandanus pachys|H.St.John
|Pandanus pakari|H.St.John
|Pandanus palkilensis|Hosok.
|Pandanus palmyraensis|H.St.John
|Pandanus pansus|H.St.John
|Pandanus paogo|H.St.John
|Pandanus papeariensis|Martelli
|Pandanus parhamii|H.St.John
|Pandanus parksii|H.St.John
|Pandanus patulior|H.St.John
|Pandanus pedunculatus|R.Br.
|Pandanus pedunculatus var. insularis|B.C.Stone
|Pandanus pedunculatus var. malagunensis|B.C.Stone
|Pandanus pedunculatus var. rendovensis|B.C.Stone
|Pandanus planus|H.St.John
|Pandanus politus|Martelli
|Pandanus ponapensis|Martelli
|Pandanus prismaticus|Martelli
|Pandanus pritchardiae H.St.John
|Pandanus prolixus|H.St.John
|Pandanus pseudomenne|Hosok.
|Pandanus pulposus|(Warb.) Martelli
|Pandanus pulposus var. cooperi|Martelli
|Pandanus puniceus|H.St.John
|Pandanus pusillus|H.St.John
|Pandanus pyriformis|(Martelli) H.St.John
|Pandanus radiatus|H.St.John
|Pandanus raiateaensis|H.St.John
|Pandanus raivavaensis|Martelli
|Pandanus raroiaensis|H.St.John
|Pandanus rectangulatus|Kaneh.
|Pandanus repens|Miq.
|Pandanus rhizophorensis|H.St.John
|Pandanus rhombocarpus|Kaneh.
|Pandanus rikiteaensis|H.St.John
|Pandanus rimataraensis|H.St.John
|Pandanus rockii|Martelli
|Pandanus rotensis|Hosok.
|Pandanus rotundatus|Kaneh.
|Pandanus rurutuensis|H.St.John
|Pandanus sabotan|Blanco
|Pandanus saipanensis|Kaneh.
|Pandanus salailuaensis|Martelli
|Pandanus saltuarius H.St.John
|Pandanus samoanus|(Martelli) H.St.John
|Pandanus samoensis|Warb.
|Pandanus sanderi|Sander
|Pandanus savaiensis|(Martelli) H.St.John
|Pandanus schizocarpus|F.Br.
|Pandanus scopulorum|Martelli
|Pandanus seruaensis|H.St.John
|Pandanus sinuosus|H.St.John
|Pandanus sinuvadosus|H.St.John
|Pandanus smithii|H.St.John
|Pandanus spurius|(Willd.) Miq.
|Pandanus spurius var. weteringii|Martelli
|Pandanus stradbrookeensis|H.St.John
|Pandanus subaequalis|H.St.John
|Pandanus subhumerosus|H.St.John
|Pandanus subradiatus|H.St.John
|Pandanus subulorum|Martelli
|Pandanus suvaensis|(Martelli) H.St.John
|Pandanus sykesii|H.St.John
|Pandanus taepa|(F.Br.) H.St.John
|Pandanus tahaaensis|H.St.John
|Pandanus tahitensis|Martelli
|Pandanus tahitensis var. exiguus|J.W.Moore
|Pandanus tahitensis var. niueana|B.C.Stone
|Pandanus takaroaensis|H.St.John
|Pandanus tapeinos|H.St.John
|Pandanus taravaiensis|H.St.John
|Pandanus|tauensis Martelli
|Pandanus tectorius var. acutus|Kaneh.
|Pandanus tectorius var. angaurensis|Kaneh.
|Pandanus tectorius var. australianus|Martelli
|Pandanus tectorius var. brongniartii|Martelli
|Pandanus tectorius var. chamissonis|(Gaudich.) Martelli
|Pandanus tectorius var. cocosensis|B.C.Stone
|Pandanus tectorius f. convexus|B.C.Stone
|Pandanus tectorius var. douglasii|(Gaudich.) Martelli
|Pandanus tectorius var. drolletianus|(Martelli) B.C.Stone
|Pandanus tectorius var. exiguus|(J.W.Moore) B.C.Stone
|Pandanus tectorius var. fatyanion|Kaneh.
|Pandanus tectorius var. fragrans|Martelli
|Pandanus tectorius var. heronensis|(H.St.John) B.C.Stone
|Pandanus tectorius var. incrassatus|B.C.Stone
|Pandanus tectorius f. integrifolius|Agustika, S.Santiago & A.P.Keim
|Pandanus tectorius var. javanicus|Martelli
|Pandanus tectorius var. jonesii|F.Br.
|Pandanus tectorius var. laevigatus|(Martelli) B.C.Stone
|Pandanus tectorius var. laevis|Warb.
|Pandanus tectorius f. laevis|(Warb.) Masam.
|Pandanus tectorius var. littoralis|(Jungh.) Martelli
|Pandanus tectorius var. menziesii|(Gaudich.) Martelli
|Pandanus tectorius var. microcephalus|Martelli
|Pandanus tectorius var. novocaledonicus|Martelli
|Pandanus tectorius var. novoguineensis|Martelli
|Pandanus tectorius var. oahuensis|(Martelli) B.C.Stone
|Pandanus tectorius var. ongor|Kaneh.
|Pandanus tectorius var. parksii|(Martelli) J.W.Moore
|Pandanus tectorius var. pedunculatus|(R.Br.) Domin
|Pandanus tectorius f. philippinensis|Martelli
|Pandanus tectorius var. pulposus|Warb.
|Pandanus tectorius var. sanderi|(Sander) B.C.Stone
|Pandanus tectorius var. sandvicensis|Warb.
|Pandanus tectorius var. savaiensis|Martelli
|Pandanus tectorius var. spiralis|Martelli
|Pandanus tectorius var. stradbrookensis|(H.St.John) B.C.Stone
|Pandanus tectorius var. sumbavensis|Martelli
|Pandanus tectorius var. suringaensis|Martelli
|Pandanus tectorius var. taepa|F.Br.
|Pandanus tectorius var. timorensis|Martelli
|Pandanus tectorius var. tubuaiensis|(Martelli) B.C.Stone
|Pandanus tectorius var. uapensis|F.Br.
|Pandanus tectorius var. upoluensis|Martelli
|Pandanus tectorius var. yorkensis|(H.St.John) B.C.Stone
|Pandanus tectorius var. zollingeri|Martelli
|Pandanus terrireginae|H.St.John
|Pandanus tessellatus|Martelli
|Pandanus tikeiensis|H.St.John
|Pandanus tima|H.St.John
|Pandanus timoeensis|H.St.John
|Pandanus tolotomensis|Glassman
|Pandanus tomilensis|Kaneh.
|Pandanus tongaensis|H.St.John
|Pandanus trapaneus|H.St.John
|Pandanus tritosphaericus|H.St.John
|Pandanus trukensis|Kaneh.
|Pandanus tuamotensis|F.Br.
|Pandanus tuamotensis var. locularis|F.Br.
|Pandanus tuamotensis var. typica|F.Br.
|Pandanus tubuaiensis|Martelli
|Pandanus tupaiensis|H.St.John
|Pandanus tutuilaensis|Martelli
|Pandanus uea|H.St.John
|Pandanus upoluensis|(Martelli) Martelli
|Pandanus upoluensis var. angulosus|Martelli
|Pandanus upoluensis var. minor|Martelli
|Pandanus utiyamae|Kaneh.
|Pandanus vahitahiensis|H.St.John
|Pandanus vandra|H.St.John
|Pandanus vangeertii|Van Geert ex T.Moore & Mast.
|Pandanus variegatus|Miq.
|Pandanus veitchii|Mast.
|Pandanus virginalis|H.St.John
|Pandanus viri|H.St.John
|Pandanus viridinsularis|H.St.John
|Pandanus volkensii|Kaneh.
|Pandanus wilderi|H.St.John
|Pandanus yorkensis|H.St.John
|Pandanus yunckeri|H.St.John
}}
}}

'''''Pandanus tectorius''''' is a species of ''[[Pandanus]]'' (screwpine) that is native to [[Malesia]], [[Papuasia]], eastern Australia, and the Pacific Islands. It grows in the coastal lowlands typically near the edge of the ocean.<ref name=":0">{{Cite web|url=http://wildlifeofhawaii.com/flowers/1091/pandanus-tectorius-hala/|title=Pandanus tectorius- Hala|last=Kinsey|first=Beth|date=2017|website=Wild Life of Hawaii|access-date=6 April 2017}}</ref> Common names in English include '''thatch screwpine''',<ref name=GRIN>{{GRIN | ''Pandanus tectorius'' | access-date = 17 Sep 2016 }}</ref> '''Tahitian screwpine''',<ref name=PLANTS>{{PLANTS | symbol = PATE2 | taxon = Pandanus tectorius | access-date = 17 Sep 2016 }}</ref> '''hala tree'''<ref>{{Cite web|url=http://nativeplants.hawaii.edu/plant/view/Pandanus_tectorius|title=Native Plants Hawaii - Viewing Plant : Pandanus tectorius|website=nativeplants.hawaii.edu}}</ref> ({{lang|haw|{{wikt-lang|haw|pū}} hala}} in Hawaiian)<ref>{{cite book |last=Pukui |first=Mary Kawena |display-authors=etal |title=Hawaiian Dictionary |date=1986 |publisher=Univ. of Hawaii Press |isbn=978-0-8248-0703-0 |url=https://books.google.com/books?id=bHdRhjL9Y9EC&pg=RA1-PA348 |quote={{lang|haw|pū hala}}. {{abbr|n.|noun}} pandanus tree. […] {{lang|haw|Ulu pū hala}}, pandanus grove.}}</ref> and '''pandanus'''.<ref name=":1">{{Cite web |year=2002 |title=Pandanus tectorius |url=http://www2.hawaii.edu/~eherring/hawnprop/pan-tect.htm |website=College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa}}</ref> The fruit is edible and sometimes known as '''hala fruit'''.

==Description==
''P. tectorius'' is a small [[tree]] that grows upright to reach {{convert|4|-|14|m|ft|abbr=on}} in height.<ref name=":0" /> The single trunk is slender with brown ringed bark.<ref name=":1" /> It is spiny, grows to 4.5–11 m (15–35&nbsp;ft) in width,<ref name=":1" /> and forks at a height of {{convert|4|-|8|m|ft}}.<ref name="agroforestry"/> It is supported by aerial roots (prop roots) that firmly anchors the tree to the ground.<ref name=":1" /> Roots sometimes grow along the branch,<ref name=":0" /> and they grow at wide angles in proportion to the trunk.<ref name=":1" />

<gallery>
林投 20190525170309.jpg|Growth habit
林投 20190530190950.jpg|Aerial roots
林投帶刺氣生根與新葉 20190525170359.jpg|Spiny aerial roots and leaflets
Pandanus tectorius fruit.jpg|Fruit showing phalanges
</gallery>

===Flowers===

[[File:Hīnano - panoramio.jpg|thumb|Male flower]]
''Pandanus tectorius'' is [[dioecy|dioecious]], meaning male and female flowers are borne on separate trees,<ref name=":0" /> with very different male and female flowers. Male flowers, known as [[raceme]]s, are small, fragrant, and short-lived, lasting only a single day. The flowers are grouped in 3 and gathered in large clusters<ref name=":1" /> surrounded by big, white [[bract]]s.<ref name=":0" /> these clusters are about 1&nbsp;ft in length and are fragrant.<ref name=":1" /> Female flowers resemble pineapples.<ref name="agroforestry"/>

In Hawaiʻi the male flower is called ''hīnano'' and the bracts are used for making very fine mats (''moena hīnano''' or ''ʻahu hīnano'').<ref>{{Hawaiian Dictionaries|hīnano|id=D100078}}</ref>

===Fruit===
The female ''P. tectorius'' trees produce a segmented, large [[fruit]].<ref name=":0" /> Although not closely related,<ref name=":1" /> the fruit resembles a pineapple.<ref name=":1" /> The fruit of ''P.&nbsp;tectorius'' is either [[Oval|ovoid]], [[ellipsoid]], subglobose or [[Sphere|globose]] with a diameter of {{convert|4|-|20|cm|in|abbr=on}} and a length of {{convert|8|-|30|cm|in|abbr=on}}.<ref name=":1" /> The fruit is made up of 38–200 wedge-like phalanges, often referred to as keys or [[Gynoecium|carpels]], which have an outer fibrous husk and are 8 inches in length.<ref name=":1" /> There are roughly 40 to 80 keys in each fruit and the color of the fruit can be yellow, orange, or red with a green top.<ref name=":0" /> Phalanges contain two seeds on average, with a maximum of eight reported. The phalanges are buoyant, and the seeds within them can remain viable for many months while being transported by ocean currents.<ref name="agroforestry"/>

=== Leaves ===
The leaves of ''Pandanus tectorius'' are usually {{convert|90|-|150|cm|ft|abbr=on}} in length<ref name=":0" /> and {{convert|5|-|7|cm|in|abbr=on}} in width.<ref name=":1" /> They possess saw-like margins.<ref>{{Cite web |url=http://nativeplants.hawaii.edu/plant/view/Pandanus_tectorius |title=Pandanus tectorius |date=2009 |website=Native Plants Hawaii |archive-url=https://web.archive.org/web/20230131130653/http://nativeplants.hawaii.edu/plant/view/pandanus_tectorius/ |archive-date=31 Jan 2023 |url-status=dead |access-date=7 May 2023}}</ref> Some varieties have spines along the edges and ribs throughout the leaves.<ref name=":1" /> The leaves are spirally arranged at the end of the branches.<ref name=":1" />

== Taxonomy ==
''Pandanus tectorius'' was first described by [[Sydney Parkinson]] in 1774.<ref name="POWO"/> It is an [[Flowering plant|angiosperm]] belonging to the genus ''[[Pandanus]]'' of the family [[Pandanaceae]].<ref>{{Cite journal|title=Classification for Kingdom Plantae Down To Genus Pandanus L. f.|url=https://plants.usda.gov/java/ClassificationServlet?source=display&classid=PANDA|journal=Natural Resources Conservation Service}}</ref>

==Distribution==
''Pandanus tectorius'' grows natively from the [[Philippines]] through the [[Pacific Ocean]] to [[Hawaii]]. It is found in parts of [[Malesia]] (the [[Cocos (Keeling) Islands]], [[Java]], the [[Lesser Sunda Islands]], the [[Maluku Islands]] and the [[Philippines]]), throughout [[Papuasia]], and in most of the tropical Pacific.<ref name="POWO"/> In Australia, it is native to an area from [[Sea Acres National Park|Port Macquarie]] in [[New South Wales]] to northern [[Queensland]].<ref name="RFK8">{{cite web |url=https://apps.lucidcentral.org/rainforest/text/entities/pandanus_tectorius.htm |title=Pandanus tectorius |author=F.A. Zich |author2=B.P.M Hyland |author3=T. Whiffen |author4=R.A. Kerrigan |website=[[Australian Tropical Rainforest Plants]], Edition 8 |year=2020
|publisher=[[Commonwealth Scientific and Industrial Research Organisation]] (CSIRO)
|access-date=5 March 2021}}</ref> Both the US and the Hawaiian Islands recognize only one indigenous species, ''P. tectorius''.<ref name=":4">{{Cite web |title=Pandanus tectorius Parkinson ex Zucc. |url=http://plants.usda.gov/plant-profile?symbol=PATE2 |website=USDA Natural Resources Conservation Service}}</ref><ref name=":1" /> Its exact native range is unknown due to extensive cultivation; it may be an early [[Polynesian culture|Polynesian]] introduction to many of the more isolated Pacific islands on which it occurs. These islands include [[Micronesia]] and [[Melanesia]].<ref name=":4" />  In Hawaii, ''P. tectorius''  is found natively on all the main islands except [[Kahoolawe|Kahoʻolawe]],<ref name=":1" /> and it is known to have predated human settlement, based on seed and pollen samples taken from [[Kauai|Kaua{{okina}}i]]'s [[Makauwahi Cave]].<ref>{{cite news |url=http://the.honoluluadvertiser.com/article/2005/Sep/28/ln/FP509280357.html |title=Kaua'i cave tells 10,000-year tale |first=Jan |last=TenBruggencate |website=Honolulu Advertiser |date=2005-09-28}}</ref>

==Habitat==
''Pandanus tectorius'' naturally grows in coastal regions, such as on [[mangrove]] margins and beaches,<ref name="agroforestry"/> at elevations from sea level to {{convert|610|m|ft|abbr=on}}.<ref name="CFTH">{{cite journal |url=http://www2.ctahr.hawaii.edu/forestry/trees/CommonTreesHI/CFT_Pandanus_tectorius.pdf |title=Hala, screwpine |first=Elbert L. Jr. |last=Little |author2=Roger G. Skolmen  |journal=Common Forest Trees of Hawaii (Native and Introduced) |publisher=United States Forest Service |year=1989 |archive-url=https://web.archive.org/web/20170808193151/https://www.ctahr.hawaii.edu/forestry/trees/CommonTreesHI/CFT_Pandanus_tectorius.pdf |archive-date=8 Aug 2017 |url-status=dead |access-date=7 May 2023}}</ref> It requires {{convert|1500|–|4000|mm|in|abbr=on}} of annual rainfall and seasons will fluctuate from wet to dry.<ref name=":2">{{Cite web |last=Pasiecznik |first=N. |year=2015 |title=Pandanus tectorius (screw pine) |website=CABI Digital Library |url=https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.38447 |doi=10.1079/cabicompendium.38447 |publisher=Centre for Agriculture and Bioscience International |doi-access=free }}</ref>

''Pandanus tectorius'' is considered more drought tolerant than coconut trees. The trees have adapted to drought by reducing fruiting.<ref>{{Cite book |title=Growing plants on atoll soils |last1=Stone |first1=E.L. |last2=Migyar |first2=L. |last3=Robison |first3=W.L. |publisher=Lawrence Livermore National Laboratory |year=2000 |location=Livermore |page=25}}</ref> Thatch Screwpine is well adapted to grow in the many soil types present on coasts, including [[quartz]] sand, [[coral sand]], and [[peat]], as well as in [[limestone]] and [[basalt]].<ref name=":2" /> ''P. tectorius'' is salt and wind tolerant and favors slightly [[acid]]ic to [[base (chemistry)|basic]] soil ([[Soil pH|pH]] of 6–10). The trees are strong and can typically withstand tropical storms.<ref name="agroforestry">{{Cite web |last1=Thomson |first1=L.A.J. |last2=Englberger |first2=L.|last3=Guarino |first3=L. |last4=Thaman |first4=R.R. |last5=Elevitch |first5=C.|year=2006 |title=Pandanus tectorius (pandanus) |url=https://agroforestry.org/images/pdfs/P.tectorius-pandanus.pdf |website=Agroforestry.org |access-date=7 May 2023}}</ref> It prefers to grow in full sunlight, but grows well with 30-50% shade. It will not tolerate shade above 70%.<ref name="agroforestry" />

==Ecology==
There are a wide range of natural enemies that pose a threat to ''P. tectorius'' such as [[Parasitism|parasites]], [[pathogen]]s, and [[herbivore]]s. They attack the leaves, roots, stems, and growing points.<ref name=":2" /> The [[Phasmatidae|stick insect]] ''[[Megacrania batesii]]'' lives and feeds only on ''P. tectorius'' and two other ''Pandanus'' species.

''Pandanus tectorius'' in Australia is threatened by a sap-sucking insect, ''Jamella australiae'', a species of the genus ''[[Jamella]]'' of the subfamily [[Flatinae]],<ref>{{cite web |title=Species: Jamella australiae (Pandanus Planthopper) |website=Atlas of Living Australia |url=https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:a9177d9c-7d83-4237-9e31-90d0ee1358db |access-date=4 January 2021}}</ref> known as the Pandanus planthopper.<ref name=byfield>{{cite news |last=Stünzner |first=Inga |title=Byfield National Park becomes last line of defence against threat to pandanus |website=ABC News |publisher=[[Australian Broadcasting Corporation]] |date=15 December 2020 |url=https://www.abc.net.au/news/2020-12-16/pandanus-planthopper-kills-60000-plants-and-heads-north/12985874 |access-date=4 January 2021}}</ref> It has caused much damage to plants on the northern coast of [[New South Wales]],<ref name=tweed>{{cite web |title=Pandanus Dieback |website=Tweed Shire Council |date=29 September 2016 |url=https://www.tweed.nsw.gov.au/Item/927 |archive-url=https://web.archive.org/web/20210104062326/https://www.tweed.nsw.gov.au/Item/927 |archive-date=4 Jan 2021 |url-status=dead |access-date=7 May 2023}}</ref> before making its way up the coast to [[Noosa]] and the [[Gold Coast, Queensland|Gold Coast]] in Queensland in the 1990s. Since then it has infested pandanus further north, killing about 80 per cent of the ''P. tectorius'' population to the south of [[Gladstone, Queensland]], and has since reached [[Yeppoon]] on the [[Capricorn Coast]], where ''P. tectorius''  plays an important part in preventing [[coastal erosion]].<ref name=byfield/> A natural predator in the form of a wasp native to northern Queensland, ''[[Aphanomerus pusillus]]'', has been introduced on [[Fraser Island]]<ref>{{cite news |title=The insects killing Fraser Island's pandanus population |newspaper=The Courier Mail |date=26 January 2017 |url=https://www.couriermail.com.au/news/queensland/gympie/the-insects-killing-fraser-islands-pandanus-population/news-story/39f31a04a0d8f7a13d23a447e78d3848 |access-date=4 January 2021}}</ref><ref name=coghill>{{cite news |last=Coghill |first=Jon |title=Rangers turn to tiny native wasp to save Fraser Island's iconic pandanus population |website=ABC News |publisher=[[Australian Broadcasting Corporation]] |date=29 October 2015 |url=https://www.abc.net.au/news/2015-10-29/fraser-island-wasp-saving-pandanus-trees/6895454 |access-date=4 January 2021}}</ref> and in [[Byfield National Park]]<ref name=byfield/> as one of methods used to combat the pest. Other methods used on Fraser Island including the injection of insecticide into the plant, stripping infested leaves away, and breeding new plants from local stock. The wasp can only be used in the warmer months on the island, as it does not thrive in the cooler climate of southern Queensland.<ref name=coghill/>

== Cultivation ==
''Pandanus tectorius'' may be grown from seed or cuttings – the former will flower at around 15 years and the latter  usually flowers by 3 to 4 years of age.<ref name="agroforestry" /> Female trees typically flower 1 to 3 times per year while male trees will flower every 2 months.<ref name=":1" /> It is thought to reproduce sexually in Hawaii, but there is some evidence that [[apomixis]] occurs.<ref name=":1" /> Small insects, such as bees, and wind are usually the pollinators.<ref name=":1" /> It takes 1 to 2 years from pollination to produce fruit on female trees.<ref name=":2" />

Seasons vary amongst locations and varieties.<ref name=":2" /> For example, in [[Fiji]] the pollination season is March to May, in northern Australia it is April to August, and in [[Micronesia]], there are two season December to March and July to September.<ref name=":2" /> Most varieties produce 8 to 12 fruits per tree every 2 years.<ref name="agroforestry" /> Each fruit usually weighs between {{cvt|7|and|15|kg}} and contains 35 to 80 edible keys.<ref name="agroforestry" />

''Pandanus tectorius'' plants are usually propagated by seed in Hawaii.<ref name=":2" /> Soak the keys in cool tap water for 5 days while frequently changing the water.<ref name=":5">{{Cite book |title=Growing native Hawaiian plants: a how-to guide for the gardner |last=Bornhorst |first=Heidi L. |publisher=The Bess Press |year=1996 |location=Honolulu |pages=52–53}}</ref> Viable keys will float, so it is important to keep them. In ''Growing native Hawaiian plants: a how-to guide for the gardner'', Bornhorst says to remove the fleshy layer of the key and then bury the seed half-way in planting soil. It is important to keep the soil moist.<ref name=":5" />

''P. tectorius'' can also be grown from large cuttings. Selected forms are propagated by stem cuttings in Micronesia.<ref name=":2" /> Morphological traits looked for include aerial roots. Plants selected have 2/3 of their leaves trimmed off to prevent water loss.<ref name=":2" /> In Native Hawaiian plants for tropical seaside landscaping, Moriarty says for best results use mature branches with leaves and small aerial roots. Then root in a sand bed.<ref name=":6">{{Cite journal |last=Moriarty |first=Dan |year=1975 |title=Native Hawaiian plants for tropical seaside landscaping |journal=Bulletin of the Pacific Tropical Botanical Garden |volume=3 |pages=41–48}}</ref> Plants grown from cuttings produce fruit in 4 to 6 years.<ref name=":6" />

Propagation by grafting is not applicable.<ref name=":2" />

==Uses==
The fruit of ''Pandanus tectorius'' is edible. Some varieties and [[cultivar]]s contain significant amounts of [[calcium oxalate]], so need thorough cooking before being consumed.<ref name=Arno14>{{Citation |mode=cs1 |last1=Arnold |first1=Michael A. |date=2014 |title=''Pandanus tectorius'' S. Parkinson |website=Aggie Horticulture |publisher=Texas A&M University |url=https://aggie-horticulture.tamu.edu/syllabi/206/Lists/Fourth%20Edition/Pandanustectorius.pdf |access-date=2020-09-30 |archive-date=2021-08-31 |archive-url=https://web.archive.org/web/20210831185729/https://aggie-horticulture.tamu.edu/syllabi/206/Lists/Fourth%20Edition/Pandanustectorius.pdf |url-status=dead }}</ref> Other cultivars contain very little to no calcium oxalate and can be eaten raw. It is an important food source in the atolls of [[Micronesia]] and [[Polynesia]], with the fruit commonly eaten raw or turned into a dried paste (e.g., [[mokwan (food)|mokwan]] in the [[Marshall Islands]] or [[te tuae]] in [[Kiribati]]<ref name=":8989">{{cite magazine |author=<!-- not stated --> |date=2006 |title=Pacific food leaflet No. 6 - Pandanus |url=https://www.spc.int/digitallibrary/get/fn7vm |magazine=Pacific food leaflet |location=Noumea |publisher=Secretariat of the Pacific Community |access-date=17 June 2025}}</ref>) or flour.<ref>{{cite journal |author1=Miller, C.D. |author2=Murai, M. |author3=Pen, F. |year=1956 |title=The Use of Pandanus Fruit As Food in Micronesia |journal=Pacific Science |volume=10 |issue=1 |pages=3–16 |url=http://scholarspace.manoa.hawaii.edu/bitstream/10125/8178/1/v10n1-3-16.pdf |access-date=7 May 2023}}</ref> It is also one of the traditional foods of [[Maldivian cuisine]].<ref>{{Cite journal|url=https://www.academia.edu/4398927|title=Eating on the Islands - As times have changed, so has the Maldives' unique cuisine and culture|first=Xavier|last=Romero-Frias|journal=Himalmag |date=15 April 2013|volume=26 |issue=2}}</ref> The fibrous nature of the fruit also serves as a natural dental floss.{{cn|date=May 2023}} It is also used in Samoan culture as a ''ula fala'', a necklace made out of the dried fruit painted in red and is worn by the [[fa'amatai|matai]] during special occasions and functions.<ref>{{cite web|title=Samoan 'Ula Fala |url=http://www.blackpearldesigns.com/collections/samoan-handicrafts/products/samoan-ula-fala |website=blackpearldesigns |access-date=3 October 2015}}</ref>

Australian Aboriginal peoples extracted the slender, edible seeds. This seed, and the fruit, was an important food.<ref>{{Cite book |last=Low |first=Tim |title=Wild food plants of Australia |publisher=HarperCollinsPublishers |year=1991 |isbn=0-207-16930-6 |location=Sydney, NSW |page=42}}</ref>

The tree's leaves are often used as flavoring for sweet dishes. It is also used in Sri Lankan cookery, where the leaves are used to flavor a variety of curries. Leaves were used by the [[Polynesians]] to make baskets, mats, outrigger canoe sails, thatch roofs,<ref>{{cite news |url=http://archives.starbulletin.com/2007/06/26/news/story09.html |title=Funds help hala trees strengthen isle roots |first=Gary |last=Kubota |date=26 June 2007 |work=[[Honolulu Star-Bulletin]] |archive-url=https://web.archive.org/web/20201125113819/http://archives.starbulletin.com/2007/06/26/news/story09.html |archive-date=25 November 2020}}</ref> and grass skirts.

The fragrant male flowers are used in perfumery and are also distilled to make [[Kewra]].{{Citation needed|date=September 2020}}

A large shrub or small tree of immense cultural, health, and economic importance in the Pacific, it is second only to coconut on atolls. It grows wild mainly in semi-natural vegetation in [[Littoral zone|littoral]] habitats throughout the tropical and subtropical Pacific, where it can withstand drought, strong winds, and salt spray. It propagates readily from seed, but it is also widely propagated from branch cuttings by local people for farms and home gardens. It grows fairly quickly, and all parts are used, from the nutritious fruits of edible varieties to the poles and branches in construction to the leaves for weaving and garlands. The plant is prominent in Pacific culture and tradition, including local medicine.{{Citation needed paragraph|date=August 2021}}

Hundreds of cultivated varieties are known by their local names and characteristics of fruits, branches, and leaves. At present, there is evidence that this diversity is declining, with certain varieties becoming difficult to find. The reasons include less replanting, deforestation, fire, flagging interest by the new generation, and rapid population growth leading to urbanization.<ref name="agroforestry"/>

==Culture==
The seal of [[Punahou School]] in [[Honolulu]], Hawaii, features the hala tree, in part because [[lauhala]], the art of weaving with the leaves of that tree, is pivotal to the history of the island, with everything from houses to pillows being made in this fashion. Local legend tells of an aged Hawaiian couple who lived long ago above the present Punahou campus, and had to travel far for water. They prayed each night for a spring, but to no avail. Finally one night, in a dream answering their prayers, they were told to uproot the stump of an old hala tree. They did as they were told and found a spring of clear, sweet water, which they named Ka Punahou, the New Spring. According to legend, Punahou School's lily pond is fed by this same spring.{{Citation needed paragraph|date=August 2021}}

== Gallery ==
<gallery mode="packed">
File:Pandanus tectorius fruit (riped).JPG|Ripe fruit
File:Pandanus.jpg|Fruit
File:Pandanus tectorius (5187732877).jpg|Roots
File:Owoce Pandan.jpg|Close up of keys, or [[stamen]]
File:Pandanus tectorius aerial roots trained as an arch at Guam Zoo, Tumon.jpg|Aerial roots trained as an arch, Guam Zoo
</gallery>

==See also==
* [[Domesticated plants and animals of Austronesia]]
* [[List of endemic plants in the Mariana Islands]]

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

==External links==
{{Commons category}}
{{Wikispecies}}
* [http://www.um.es/eubacteria/Pandanus_tectorius.jpg ''Pandanus tectorius'' from Foster Garden, Honolulu, Oahu Island, Hawai'i] [http://www.um.es/eubacteria/plantae.html World plants, visual gallery] University of Murcia. Spain
* NSW Department of Environment & Climate Change [http://www.environment.nsw.gov.au/vegetation/PandanusDieback.htm]
* Australian Native Plants - John W. Wrigley & Murray Fagg {{ISBN|1-876334-90-8}}
* Christenhusz, M.J.M. (2009). Typification of ornamental plants: ''Pandanus tectorius'' (Pandanaceae). ''[[Phytotaxa]]'' 2: 51–52.
* [http://flickrhivemind.net/Tags/puhala/ The World's Best Photos of puhala], Flickr Hive Mind, flickrhivemind.net, related pictures, also the fruits partially dismantled

{{US state flowers}}
{{Taxonbar|from=Q312736}}
{{Authority control}}

[[Category:Pandanus|tectorius]]
[[Category:Oceanian cuisine]]
[[Category:Gilbertese cuisine]]
[[Category:Marshallese cuisine]]
[[Category:Micronesian cuisine]]
[[Category:Polynesian cuisine]]
[[Category:Flora of Malesia]]
[[Category:Flora of Papuasia]]
[[Category:Flora of New South Wales]]
[[Category:Flora of Queensland]]
[[Category:Flora of the Pacific]]
[[Category:Plants described in 1773]]
[[Category:Edible fruits]]
[[Category:Austronesian agriculture]]