View source for Biology:Metroxylon sagu

{{Short description|Species of palm}}
{{Italic title}}
{{Speciesbox
| name          = Sago palm
| image         = 1989.05-086-27atp Sago palm(Metroxylon sagu)(if(div stages),it i-s) Waipirit(W.Seram,Maluku),ID sat13may1989.jpg
| image_caption = Sago palms with characteristic terminal [[Biology:Inflorescence|inflorescence]]/[[Biology:Infructescence|infructescence]] (West Seram, Maluku, Indonesia)
| status        = LC
| status_system = IUCN3.1
| status_ref    = <ref name=IUCN>{{cite iucn | author1 = Rahman, W. | author2 = IUCN SSC Global Tree Specialist Group | author3 = Botanic Gardens Conservation International (BGCI) | name-list-style = amp | title = ''Metroxylon sagu'' | page = e.T155290240A155290242 | year = 2021 | access-date = 7 February 2023}}</ref>
| genus         = Metroxylon
| species       = sagu
| authority     = Rottb.<ref name=POWO>{{cite POWO | title = ''Metroxylon sagu'' | id = 668244-1| access-date = 22 February 2023}}</ref>
| synonyms      = 
* ''Metroxylon hermaphroditum'' {{Au|Hassk.}}
* ''Metroxylon inerme'' {{Au|(Roxb.) Mart.}}
* ''Metroxylon laeve'' {{Au|(Giseke) Mart.}}
* ''Metroxylon longispinum'' {{Au|(Giseke) Mart.}}
* ''Metroxylon micracanthum'' {{Au|Mart.}}
* ''Metroxylon oxybracteatum'' {{Au|Warb. ''ex'' K.Schum. & Lauterb.}}
* ''Metroxylon rumphii'' {{Au|(Willd.) Mart.}}
* ''Metroxylon squarrosum'' {{Au|[[Biography:Odoardo Beccari|Becc.]]}}
* ''Metroxylon sylvestre'' {{Au|(Giseke) Mart.}}
* ''Sagus americana'' {{Au|Poir.}}
* ''Sagus genuina'' {{Au|Giseke}}
* ''Sagus inermis'' {{Au|Roxb.}}
* ''Sagus koenigii'' {{Au|Griff.}}
* ''Sagus laevis'' {{Au|Jack}}
* ''Sagus longispina'' {{Au|(Giseke) Blume}}
* ''Sagus micracantha'' {{Au|(Mart.) Blume}}
* ''Sagus rumphii'' {{Au|Willd.}}
* ''Sagus sagu'' {{Au|(Rottb.) H.Karst.}}
* ''Sagus spinosa'' {{Au|Roxb.}}
* ''Sagus sylvestris'' {{Au|(Giseke) Blume}}
| synonyms_ref = <ref name=POWO/>
}}

'''''Metroxylon sagu''''', the '''true sago palm''', is a species of [[Biology:Arecaceae|palm]] in the genus ''[[Biology:Metroxylon|Metroxylon]]'', native to tropical southeastern Asia. The tree is a major source of [[Chemistry:Sago|sago]] starch.

== Description ==
True sago palm is a [[Biology:Basal shoot|suckering]] (multiple-stemmed) palm, each stem only flowering once (hapaxanthic) with a large upright terminal [[Biology:Inflorescence|inflorescence]]. A stem grows {{Convert|7–25|m|abbr=off}} tall before it ends in an [[Biology:Inflorescence|inflorescence]].<ref name=dls>Schuiling, D.L. (2009) ''Growth and development of true sago palm (''Metroxylon sagu ''Rottbøll) with special reference to accumulation of starch in the trunk: a study on morphology, genetic variation and ecophysiology, and their implications for cultivation''. (PhD thesis Wageningen University).</ref>

Before flowering, a stem bears about 20 pinnate leaves up to {{Convert|10|m|abbr=on}} long. Each leaf has about 150–180 [[Biology:Leaflet (botany)|leaflets]] up to {{Convert|175|cm|ft|frac=2}} long. The inflorescence, {{Convert|3–7.5|m|abbr=on|frac=2}} tall and wide, consists of the continuation of the stem and 15–30 upwardly-curving (first-order) branches spirally arranged on it. Each first-order branch has 15–25 rigid, distichously arranged second-order branches; each second-order branch has 10–12 rigid, distichously arranged third-order branches. Flower pairs are spirally arranged on the third-order branches, each pair consisting of one male and one hermaphrodite flower. The fruit is [[Biology:Drupe|drupe]]-like, about {{Convert|5|cm|abbr=on|frac=4}} in diameter, covered in scales which turn from bright green to straw-coloured upon ripening.<ref name="dls" />

The sago palm reproduces by fruiting. Each stem (trunk) in a sago palm clump flowers and fruits at the end of its life, but the sago palm as an individual organism lives on through its suckers (shoots that are continuously branching off a stem at or below ground level).<ref name="dls" />

== Distribution and habitat ==
''Metroxylon sagu'' is native to the Maluku Islands and New Guinea. It has been naturalised in other parts of tropical Asia, including Sumatra, Borneo and Thailand.<ref name=IUCN/><ref name=POWO/> Its habitat is in lowland swamp forests.<ref name=IUCN/>

== Uses ==
{{Main|Chemistry:Sago}}

The tree is of commercial importance as the main source of sago, a [[Chemistry:Starch|starch]] obtained from the trunk by washing the starch kernels out of the pulverized pith with water. A trunk cut just prior to flowering contains enough sago to feed a person for a year.<ref name=":0">{{Cite book |url=https://www.worldcat.org/oclc/277203364 |title=The Complete Guide to Edible Wild Plants |publisher=Skyhorse Publishing |others=United States Department of the Army |year=2009 |isbn=978-1-60239-692-0 |location=New York |pages=88 |language=en-US |oclc=277203364}}</ref> Sago is used in cooking for puddings, noodles, breads, and as a thickener. In the Sepik River region of New Guinea, pancakes made from sago are a staple food, often served with fresh fish. Its leaflets are also used as thatching which can remain intact for up to five years.<ref>Palm and Cycad Societies of Australia. [http://www.pacsoa.org.au/palms/Metroxylon/sagu.html Palms: Metroxylon sagu]. Retrieved 28 February 2012</ref> The dried petioles (called ''gaba-gaba'' in Indonesian) are used to make walls and ceilings; they are very light, and therefore also used in the construction of rafts.

To harvest the starch in the stem, it is felled shortly before or early during its final flowering stage when starch content is highest. Sago palm is  propagated by man by collecting (cutting) and replanting young suckers rather than by seed.<ref name="dls" />

The upper portion of the trunk's core can be roasted for food; the young nuts, fresh shoots and palm cabbage are also edible.<ref name=":0" />

Recent research indicates that the sago palm was an important food source for the ancient people of coastal China, in the period prior to the cultivation of rice.<ref>{{Cite web|url=https://www.sciencedaily.com/releases/2013/05/130508172138.htm|title = In ancient China, sago palms were major plant food prior to rice cultivation}}</ref>

== Culture ==
Sago was noted by the Chinese historian Zhao Rukuo (1170–1231) during the Song Dynasty. In his ''Zhu Fan Zhi'' (1225), a collection of descriptions of foreign countries, he writes that the kingdom of Boni "...produces no wheat, but hemp and rice, and they use ''sha-hu'' (sago) for grain".

== References ==
{{Reflist}}

== External links ==

{{Non-timber forest products}}
{{Taxonbar|from=Q164088}}

[[Category:Metroxylon|sagu]]

{{Sourceattribution|Metroxylon sagu}}