View source for Biology:Metrosideros polymorpha

{{short description|Species of plant}}
{{speciesbox
 |name          = ''{{okina}}Ōhi{{okina}}a lehua''
 |image         = Metrosideros polymorpha.jpg
 |image_caption = ''{{okina}}Ōhi{{okina}}a lehua'' flowers
 |genus         = Metrosideros
 |species       = polymorpha
 |authority     = [[Biography:Charles Gaudichaud-Beaupré|Gaudich.]]
 |synonyms      =
  {{collapsible list |
    {{plainlist | style = margin-left: 1em; text-indent: -1em; |
* ''Metrosideros collina'' f. ''lurida'' rock
* ''Metrosideros collina'' f. ''sericea'' Rock
* ''Metrosideros collina'' f. ''strigosa'' Rock
* ''Metrosideros collina'' subsp. ''polymorpha'' (Gaudich.) Rock
* ''Metrosideros collina'' var. ''glaberrima'' (H.Lév.) Rock
* ''Metrosideros collina'' var. ''glabrifolia'' (A.Heller) Rock
* ''Metrosideros collina'' var. ''haleakalesis'' Rock
* ''Metrosideros collina'' var. ''hemilanata'' Hochr.
* ''Metrosideros collina'' var. ''imbricata'' Rock
* ''Metrosideros collina'' var. ''incana'' (H.Lév.) Rock
* ''Metrosideros collina'' var. ''macrophylla'' Rock
* ''Metrosideros collina'' var. ''newellii'' Rock
* ''Metrosideros collina'' var. ''prostrata'' Rock
* ''Metrosideros collina'' var. ''pumila'' (A.Heller) Rock
* ''Metrosideros hillebrandii'' H.Lév. & Vaniot
* ''Metrosideros pumila'' (A.Heller) Hochr.
* ''Nania glabrifolia'' A.Heller
* ''Nania polymorpha'' (Gaudich.) A.Heller
* ''Nania pumila'' A.Heller
    }}
  }}
 |synonyms_ref      = <ref>{{cite web|url=http://apps.kew.org/wcsp/qsearch.do|title=World Checklist of Selected Plant Families}}</ref>
 |subdivision_ranks = Varieties
 |subdivision_ref   = <ref name="TradTree" />
 |subdivision       = ''M. p.'' var. ''dieteri''<br/> ''M. p.'' var. ''glaberrima''<br/> ''M. p.'' var. ''incana''<br/>''M. p.'' var. ''macrophylla''<br/> ''M. p.'' var. ''newelli''<br/> ''M. p.'' var. ''polymorpha''<br/>''M. p.'' var. ''pumila''<br/> ''M. p.'' var. ''pseudorugosa''
}}

'''''Metrosideros polymorpha''''', the '''''{{okina}}ōhi{{okina}}a lehua''''',<ref name=Hawaiian-dicts-ohi-lehua>{{Hawaiian Dictionaries|{{okina}}ōhi{{okina}}a|id=D14972}}; {{Hawaiian Dictionaries|lehua|id=D10707}}</ref> is a species of flowering [[Biology:Evergreen|evergreen]] [[Earth:Tree|tree]] in the [[Biology:Myrtus|myrtle]] family, [[Biology:Myrtaceae|Myrtaceae]], that is [[Biology:Endemism|endemic]] to the six largest [[Earth:Hawaiian Islands|islands]] of Hawai{{okina}}i. It is a member of the diverse ''[[Biology:Metrosideros|Metrosideros]]'' genus, which are widespread over the [[Earth:Southwest Pacific|southwest Pacific]]. It is the state tree of Hawai‘i.<ref name=":0" />

It is a highly variable tree, being {{convert|20|-|25|m|ft|abbr=on}} tall in favorable situations, and a much smaller [[Biology:Prostrate shrub|prostrate shrub]] when growing in boggy soils or directly on [[Earth:Basalt|basalt]]. It produces a brilliant display of [[Biology:Flower|flower]]s, made up of a mass of [[Biology:Stamen|stamen]]s, which can range from fiery red to yellow. Many native Hawaiian traditions refer to the tree and the forests it forms as sacred to Pele, the [[Earth:Volcano|volcano]] goddess, and to Laka, the goddess of hula. {{okina}}Ōhi{{okina}}a trees grow easily on lava, and are usually the first plants to grow on new lava flows.

''Metrosideros polymorpha'' is commonly called a ''lehua'' tree, or an ''{{okina}}ōhi{{okina}}a lehua'', or simply an ''{{okina}}ōhi{{okina}}a''; all are correct,<ref name=Wagner-1999/> although ''{{okina}}ōhi{{okina}}a'' is also used to refer to the [[Biology:Tomato|tomato]] as well as certain varieties of [[Biology:Sugarcane|sugarcane]] and [[Biology:Taro|taro]].<ref>{{Cite web|url=https://trussel2.com/HAW/haw-o.htm#ʻōhiʻa₁|title=Combined Hawaiian Dictionary: ʻōhiʻa|website=trussel2.com}}</ref> There is a widespread but mistaken notion that the Hawai{{okina}}ian word ''{{okina}}ōhi{{okina}}a'' only refers to the tree and that the word ''lehua'' only refers to its flowers.

==Distribution==
''Metrosideros polymorpha'' is the most common native tree in the [[Earth:Hawaiian Islands|Hawaiian Islands]], tolerating a wide range of soil conditions, temperature, and rainfall. It grows from sea level right up to the [[Earth:Tree line|tree line]] at elevations of {{convert|2500|m|ft|abbr=on}} and is commonly found in moist and dry forests, high shrublands, and is a [[Earth:Ruderal species|colonizer]] of recent [[Earth:Lava|lava]] flows. It is relatively slow growing. Dominant in cloud forests above {{convert|400|m|ft|abbr=on}}, the tree is also common in seasonally wet forests, where it may be dominant or form mixtures with the native ''[[Biology:Acacia koa|Acacia koa]]''.

==Habitat==
[[File:Metrosideros polymorpha (5113316760).jpg|thumb|left|Yellow variant of the plant's flowers]]
''Metrosideros polymorpha'' may occur as a tall [[Earth:Tree|tree]] or a prostrate [[Biology:Shrub|shrub]], and everything in between. Preferred [[Chemistry:Soil|soil]]s are [[Chemistry:Acid|acid]]ic to neutral ([[Biology:Soil pH|pH]]&nbsp;3.6–7.4) and either a [[Earth:Histosol|Histosol]], [[Earth:Mollisol|Mollisol]], Podsol, [[Earth:Oxisol|Oxisol]], [[Earth:Ultisol|Ultisol]], or [[Earth:Alfisol|Alfisol]]. Rainfall of {{convert|1000|–|3000|mm|in|abbr=on}} per year is favored, but {{okina}}ōhi{{okina}}a can grow in dry forests that receive as little as {{convert|400|mm|in|abbr=on}} or bogs that get more than {{convert|10000|mm|in|abbr=on}} of rain.<ref name="TradTree">{{cite report |first1=J.B. |last1=Friday |first2=Darrell A. |last2=Herbert |date=April 2006 |title=Metrosideros polymorpha (ʻōhiʻa lehua) |publisher=The Traditional Tree Initiative |url=http://www.agroforestry.net/tti/Metrosideros-ohia.pdf}}</ref>

On moist, deep soils, {{okina}}ōhi{{okina}}a grows to {{convert|20|–|25|m|ft|abbr=on}} high. Specimens reaching {{convert|30|m|ft|abbr=on}} high are on record. The trunk varies in form. In some trees, it is straight and smooth; in others, it is twisted and prominently fluted. Trees growing in forests often have [[Biology:Root#Specialized|stilt roots]], having [[Biology:Germination|germinated]] on logs or the stems of fallen hāpu{{okina}}u (''[[Biology:Cibotium|Cibotium]]'' [[Biology:Tree fern|tree fern]]s), which have long [[Medicine:Decomposition|decayed]] away when the tree has reached maturity. Some trees have fibrous [[Biology:Aerial root|aerial root]]s to gather moisture. At high elevations, and in areas with poor soils or little rainfall, shrub forms are the norm. [[Biology:Flower|Flower]]s are usually bright to medium red but orange-red, salmon, pink, yellow, or orange forms are also found. The flowers appear in clusters on the terminal ends of the branches. Masses of [[Biology:Stamen|stamen]]s extend from the flower and give the blossoms their characteristic pom-pom shape. The stomata of the leaves are able to close up in the presence of harmful gases, which gives it an advantage over many non-native trees.<ref>{{cite web |title=Trees |website=Hawai'i Volcanoes National Park |publisher=National Park Service |url=https://www.nps.gov/havo/learn/nature/trees.htm |access-date=26 January 2021}}</ref>

==Uses==
[[File:Lehua blossoms hawaii 01.jpg|220px|thumb|''Lehua'' blossoms (''{{okina}}ōhi{{okina}}a lehua''), Hawai{{okina}}i]]
The reddish brown [[Biology:Wood#Heartwood and sapwood|heartwood]] of ''M.&nbsp;polymorpha'' is very hard, fine textured, and has a [[Physics:Specific gravity|specific gravity]] of 0.7&nbsp;.<ref name=RNGR>{{cite report |last=Allen |first=James A. |year=2003 |title=''Metrosideros polymorpha'' Gaudich |publisher=Reforestation, Nurseries and Genetics Resources  |url=http://www.rngr.net/publications/ttsm/species/PDF.2004-03-15.2731/at_download/file |url-status=live |access-date=2013-02-11 |format=[[PDF]] |archive-url=https://web.archive.org/web/20120519010409/http://www.rngr.net/publications/ttsm/species/PDF.2004-03-15.2731/at_download/file |archive-date=2012-05-19}}</ref> In native Hawaiian society, it is used in house and ''heiau'' construction, as well as to make ''papa ku{{okina}}i {{okina}}ai'' (poi boards), weapons, tool handles, ''hohoa''  (round ''[[Biology:Kapa|kapa]]'' beaters), and ''ki{{okina}}i'' (statues and idols).<ref name=Auwahi>{{cite report |first1=A.C. |last1=Medeiros |first2=C.F. |last2=Davenport |first3=C.G. |last3=Chimera |year=1998  |title=Auwahi: Ethnobotany of a Hawaiian dryland forest |publisher=Cooperative National Park Resources Studies Unit, [[Organization:University of Hawaii at Manoa|University of Hawaiʻi at Mānoa]] |url=http://www.hear.org/naturalareas/auwahi/ethnobotany_of_auwahi.pdf}}</ref> Although the trunk of ''{{okina}}ōhi{{okina}}a'' is not used to make the ''ka{{okina}}ele'' (hull) of ''wa{{okina}}a'' ([[Engineering:Outrigger canoe|outrigger canoe]]s), it was used for their ''nohona wa{{okina}}a'' (seats), ''pale'' (gunwales), and ''pola'' (decking). ''Wae'' (spreaders) were made from the curved [[Biology:Root#Specialized|stilt roots]] of ''{{okina}}ōhi{{okina}}a''. ''Pā'' (fencing) was made from the wood due to its availability; ''kauila'' (''[[Biology:Colubrina oppositifolia|Colubrina oppositifolia]]'' or ''[[Biology:Alphitonia ponderosa|Alphitonia ponderosa]]''), more durable woods when in contact with soil, was rarer. As the wood burns hot and cleanly, it is excellent ''wahie'' (firewood). The ''lehua'' (flowers) and  ''liko lehua'' (leaf buds) are used in making ''lei''.<ref name=TradTree/> The flowers were used [[Biology:Herbalism|medicinally]] to treat pain experienced during [[Medicine:Childbirth|childbirth]].<ref name=Bishop>{{cite web |title=Ohia lehua, lehua, ohia |website=Hawaiian Ethnobotany Online Database |publisher=Bernice P. Bishop Museum |url=http://data.bishopmuseum.org/ethnobotanydb/ethnobotany.php?b=d&ID=ohia_lehua |access-date=2009-02-23}}</ref>

{{okina}}Ōhi{{okina}}a lehua is one of the few [[Biology:List of honey plants|honey plants]] that is native to the Hawaiian Islands.<ref name="TradTree"/><ref>{{cite journal |first1=Kevin M. |last1=Roddy |first2=Lorna |last2=Arita-Tsutsumi |year=1997 |title=A history of honeybees in the Hawaiian Islands |journal=Journal of Hawaiian and Pacific Agriculture |volume=8 |page=61 |url=http://www.uhh.hawaii.edu/academics/cafnrm/research/documents/J_Haw_5_003.pdf}}</ref>

==Similar species==
There are about 50&nbsp;species in the genus ''[[Biology:Metrosideros|Metrosideros]]'' in [[Place:Southeast Asia|Southeast Asia]] and the Pacific and as well one species in South Africa.  The Hawaiian Islands are home to five species of ''Metrosideros'' that are ''endemic'' to the islands, meaning they are found nowhere else in the world. These are: Metrosideros polymorpha, ''[[Biology:Metrosideros macropus|M. macropus]]'', ''[[Biology:Metrosideros rugosa|M. rugosa]]'', ''M. tremuloides'', and ''M. waialealae''. The species are readily distinguished from one another by the characteristics of their leaves.<ref name=Wagner-1999/>

''[[Biology:Metrosideros kermadecensis|Metrosideros kermadecensis]]'', from the Kermadec Islands north of [[Earth:New Zealand|New Zealand]], has recently become naturalized on Maui and may become a pest species. Several [[Biology:Cultivar|cultivar]]s of ''[[Biology:Metrosideros excelsa|M. excelsa]]'', the pohutukawa tree of New Zealand, have been sometimes planted as ornamentals in Hawai{{okina}}i but are not reported to have naturalized. ''Metrosideros polymorpha'' was originally classified as a [[Biology:Variety (botany)|variety]] of ''[[Biology:Metrosideros collina|M.&nbsp;collina]]'', native to Rarotonga, Tahiti, and other islands of [[Place:Polynesia|Polynesia]], but now is generally accepted as a distinct Hawaiian endemic species.

==Conservation==
[[File:Kalapana May 2009.jpg|thumb|right|A specimen of the species [[Earth:Pioneer species|colonizing]] thirty-year-old pahoehoe flows from Kīlauea at Kalapana, Hawaii.]]
''Metrosideros polymorpha'' forests in Hawai{{okina}}i have been invaded by myriad alien species. In the wet forests these include the strawberry guava (''Psidium littorale''), albizia (''[[Biology:Falcataria moluccana|Falcataria moluccana]]''), and "purple plague" (''[[Biology:Miconia calvescens|Miconia calvescens]]''). In drier areas, problematic invaders include faya tree (''[[Biology:Myrica faya|Myrica faya]]'') and Christmasberry (''Schinus terebinthifolius''). Alien grasses such as meadow ricegrass (''[[Biology:Ehrharta|Ehrharta]] stipoides'') may form an understory that prevents or inhibits natural regeneration of the forests. In drier areas, ''M.&nbsp;polymorpha'' has to compete with silk oak (''[[Biology:Grevillea robusta|Grevillea robusta]]'') and fountain grass (''[[Biology:Pennisetum setaceum|Pennisetum setaceum]]'').

=== Rapid ʻōhiʻa death ===
{{Main|Biology:Rapid ʻŌhiʻa Death}}
[[File:Lehua flower, Alaka'i Swamp Trail, Kauaʻi.jpg|thumb|Metrosideros polymorpha flowering Alaka'i swamp in Kaua'i.]]
More recently, a strain of fungus initially identified as ''[[Biology:Ceratocystis fimbriata|Ceratocystis fimbriata]]'' has attacked the ʻōhiʻa forests of the Big Island, causing ''rapid ʻōhiʻa death''. The disease gets this name because healthy trees appear to die within a few days to a few weeks.<ref>{{cite web |title=Rapid ʻōhiʻa death |website=College of Tropical Agriculture and Human Resources |publisher=University of Hawaii |url=https://cms.ctahr.hawaii.edu/rod/ |access-date=5 March 2019}}</ref> While ''{{okina}}ōhi{{okina}}a'' itself remains extremely abundant, some species that depend on it such as the [[Biology:‘Akeke‘e|{{okina}}akeke{{okina}}e]] (''Loxops caeruleirostris'') and [[Biology:Longhorn beetle|longhorn beetle]]s in the genus ''Plagithmysus'' have become endangered due to forest areas shrinking.

In April&nbsp;2018, the cause of rapid ʻōhiʻa death was identified as two species of ''[[Biology:Ceratocystis|Ceratocystis]]'' previously unknown to science: ''C.&nbsp;huliohia'' and ''C.&nbsp;lukuohia''.<ref>{{cite news |title=Two new species of fungi that kill ʻōhiʻa trees get Hawaiian names |date=2018-04-17 |website=University of Hawaiʻi System News |url=https://www.hawaii.edu/news/2018/04/16/ohia-killing-fungi-get-hawaiian-names/ |access-date=2018-05-14 |lang=en-US}}</ref> By May&nbsp;2018, infected ʻōhiʻa trees were found on the island of [[Earth:Kauai|Kauai]], prompting requests that members of the public limit transportation of ʻōhiʻa products within the island.<ref>{{cite news |title=ʻOhiʻa fungus found on Kauai |date=2018-05-11 |department=Breaking news |newspaper=Honolulu Star-Advertiser |url=http://www.staradvertiser.com/2018/05/11/breaking-news/ohia-fungus-found-on-kauai/ |access-date=2018-05-14 |lang=en-US}}</ref>

In 2022, to assist in slowing, and hopefully ending, Rapid ʻōhiʻa Death, the ʻōhiʻa became the state tree of Hawaii thanks to a bill signed into law by Governor David Ige.<ref name=":0">{{Cite web |date=24 May 2022 |title=05/24/22 – IT'S OFFICIAL! ʻŌHIʻA LEHUA BECOMES HAWAI'I STATE ENDEMIC TREE |url=https://dlnr.hawaii.gov/blog/2022/05/24/nr22-071/ |access-date=2023-06-05 |website=Department of Land and Natural Resources |language=en}}</ref>

==Etymology==
It is a common misconception that the word ''{{okina}}ōhi{{okina}}a'' is used to refer to the tree and that the word ''lehua'' refers only to its flowers. ''The Hawaiian Dictionary''<ref>{{cite dictionary |author1=Pukui |author2=Elbert |year=1986 |title=lehua |dictionary=The Hawaiian Dictionary |page=199}}</ref> describes ''lehua'' with these words:
: "The flower of the ''{{okina}}ōhi{{okina}}a'' tree ... ''also the tree itself''" {{grey|[emphasis added]}}.
Thus endorsing the common practice of referring to ''Metrosideros polymorpha'' as a ''lehua'' tree, or as an ''{{okina}}ōhi{{okina}}a lehua'', or simply an ''{{okina}}ōhi{{okina}}a''.<ref name=Wagner-1999>{{cite book |last1=Wagner |first1=Warren Lambert |last2=Herbst |first2=D.R. |last3=Sohmer |first3=S.H. |year=1990 |title=Manual of the Flowering Plants of Hawaiʻi |edition=revised |publisher=University of Hawaii Press |place=Honolulu, HI |isbn=9780824821661 |pages=967–969 |url=https://uhpress.hawaii.edu/title/manual-of-the-flowering-plants-of-hawaii-revised-edition/ }}</ref>

The genus name ''Metrosideros'' is derived from the Greek words ''metra'', meaning 'heartwood', and ''sideron,'' meaning 'iron', and refers to the hard wood of the trees in this genus.  The specific epithet ''polymorpha,'' meaning 'many forms', is very appropriate, since individuals of this species exhibit many different morphologies and inhabit a broad range of ecological situations.<ref name="Wagner-1999" />  The [[Social:Hawaiian language|Hawaiian language]] word ''{{okina}}ōhi{{okina}}a'' is thought to have been derived from the ancestral Proto-Oceanic word, ''*kafika.''<ref name="pollex Kafika">{{Cite web|url=https://pollex.shh.mpg.de/|title=Pollex Online|website=pollex.shh.mpg.de|access-date=2019-04-12}}</ref>  Throughout Oceania, there are many similar-sounding words that were also derived from the same ancestral protoform and, in most cases, they are names for the "mountain apple", or "Malay apple" tree, ''[[Biology:Syzygium malaccense|Syzygium malaccense]].'' In the Hawaiian Islands, however, the word ''{{okina}}ōhi{{okina}}a'' is not only used to refer to ''Syzygium malaccense'', but also to other species of ''Syzygium'' and ''Metrosideros'' that occur there.<ref name=Wagner-1999/>

The derivation of the word ''lehua'' is more obscure, and while there are many opinions regarding its origin, there has been, to date, no historical linguistic study of the word to provide convincing evidence for any particular etymology.{{Citation needed|reason=Statements about absence of evidence need citations too|date=December 2021}}

==Mythology==
In Hawaiian mythology, {{okina}}Ōhi{{okina}}a and Lehua were two young lovers. The volcano goddess Pele fell in love with the handsome {{okina}}Ōhi{{okina}}a and approached him, but he turned down her advances. In a fit of jealousy, Pele transformed {{okina}}Ōhi{{okina}}a into a tree. Lehua was devastated by this transformation and out of pity the other gods turned her into a flower and placed her upon the {{okina}}ōhi{{okina}}a tree.<ref>{{cite web |title=Pele's Revenge: A Hawaii legend from Native American folklore |url=http://www.americanfolklore.net/folktales/ha2.html |access-date=2009-07-21 |archive-url=https://web.archive.org/web/20090609165100/http://americanfolklore.net/folktales/ha2.html |archive-date=2009-06-09 |url-status=dead }}</ref> Other versions say that Pele felt remorseful but was unable to reverse the change, so she turned Lehua into a flower herself.<ref>{{Cite web|url=http://www.goddessgift.com/goddess-myths/hawaiian-goddess-pele.htm|title=Pele: Goddess of the Volcano (Hawaii)|website=www.goddessgift.com|access-date=2019-04-12}}</ref> It is said that when a ''lehua'' flower is plucked from an ''{{okina}}ōhi{{okina}}a'' tree, the sky will fill with rain representing the separated lovers' tears.<ref>{{cite web |title=ʻŌhiʻa |url=https://www.nps.gov/articles/000/ohia.htm |website=Hawai'i Volcanoes National Park |publisher=U.S. National Park Service |access-date=26 January 2021}}</ref>

==References==
{{reflist}}

==Sources==
* {{cite report |author1=Medeiros, A.C. |author2=Davenport, C.F. |author3=Chimera, C.G. |date=2003-04-14 |publication-date=2009-10-28 |title=Auwahi: Ethnobotany of a Hawaiian Dryland Forest |url=http://www.hear.org/naturalareas/auwahi/ethnobotany_of_auwahi.pdf |series=Ethnobotany of Auwahi |access-date=3 January 2007}}
* {{cite book |author=Simpson, P. |year=2005 |title=Pōhutukawa & Rātā: New Zealand's iron-hearted trees |publisher=Te Papa Press}}
* {{cite report |author1=Starr, F. |author2=Starr, K. |author3=Loope, L.L. |date=27 July 2004 |section=New plant records from the Hawaiian Archipelago |editor1=Evenhuis, Neal L. |editor2=Eldredge, Lucius G.  |title=Records of the Hawaii Biological Survey for 2004 – Part&nbsp;2 |series=Bishop Museum Occasional Papers |volume=79 |pages=20–30 |publisher=Bishop Museum Press |place=Honolulu, HI}}
* {{cite report |title=Metrosideros polymorpha (ʻōhiʻa lehua) |series=Species Profiles for Pacific Island Agroforestry |date=April 2006 |id=version 3.2 |url=http://www.agroforestry.net/tti/Metrosideros-ohia.pdf |access-date=1 January 2007}}

==External links==
{{Commons}}

{{Taxonbar|from=Q2710783}}

[[Category:Metrosideros|polymorpha]]

{{Sourceattribution|Metrosideros polymorpha}}