Pongamia

{{Short description|Species of tree in the family Fabaceae}} {{Speciesbox |image = Pongamia pinnata (Karanj) near Hyderabad W IMG_7633.jpg |image_caption = Flowers |display_parents = 2 |genus = Pongamia |parent_authority = Adans. (1763), nom. cons. |species = pinnata |authority = (L.) Pierre (1898) |subdivision_ranks = Varieties |subdivision = *''Pongamia pinnata'' var. ''minor'' {{small|(Benth.) Domin}} *''Pongamia pinnata'' var. ''pinnata'' |subdivision_ref = <ref name = powo>[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:515679-1 ''Pongamia pinnata'' (L.) Pierre]. ''Plants of the World Online''. Retrieved 16 September 2023.</ref> |synonyms = {{collapsible list | {{plainlist | style = margin-left: 1em; text-indent: -1em; | * ''Cajum pinnatum'' {{small|(L.) Kuntze (1891)}} * ''Cytisus pinnatus'' <small>L. (1753)</small> * ''Galedupa pinnata'' <small>(L.) Taub. (1894)</small> * ''Millettia pinnata'' {{small|(L.) Panigrahi (1989)}} * ''Pongamia glabra'' <small>Vent. (1803), nom. superfl.</small><ref>{{cite book |last1=Heyne |first1=K. |author1-link=Karel Heyne |title=De nuttige planten van Nederlandsch-Indië, tevens synthetische catalogus der verzamelingen van het Museum voor Technische- en Handelsbotanie te Buitenzorg |date=1913 |publisher=Museum voor Economische Botanie |location=Buitenzorg |volume=II |page=306 |url=http://archive.org/stream/denuttigeplanten02heyn#page/306/mode/2up}}</ref> * ''Pongamia pinnata'' var. ''typica'' {{small|Domin (1926), not validly publ.}} * ''Derris indica'' {{small|(Lam.) Bennet}} }} }} |synonyms_ref = <ref name = powo/> }}

'''''Pongamia pinnata''''' is a species of tree in the pea family, Fabaceae, native to eastern and tropical Asia, Australia, and the Pacific islands.<ref name="powo">[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:515679-1 ''Pongamia pinnata'' (L.) Pierre]. ''Plants of the World Online''. Retrieved 16 September 2023.</ref><ref name=GRIN>{{GRIN | access-date=2010-05-02}}</ref><ref name=USDA>{{cite web |url=http://plants.usda.gov/plant-profile?symbol=mipi9 |title=Plants profile for ''Millettia pinnata'' (pongame oiltree) |work=PLANTS Profile |publisher=United States Department of Agriculture |access-date=2012-03-30}}</ref><ref name="RFK8">{{cite web |author=F.A. Zich |author2=B.Hyland |author3=T. Whiffen |author4=R.A. Kerrigan |access-date=26 May 2021 |url=https://apps.lucidcentral.org/rainforest/text/entities/Pongamia_pinnata_var._pinnata.htm |title=Pongamia pinnata var. pinnata |website=Australian Tropical Rainforest Plants (RFK8) |publisher=Centre for Plant Biodiversity Research, Australian Government}}</ref> It is the sole species in genus '''''Pongamia'''''.<ref>[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30023711-2 ''Pongamia'' Adans.] ''Plants of the World Online''. Retrieved 16 September 2023.</ref> It is often known by the synonym ''Millettia pinnata''. Its common names include '''Indian beech''', '''Karanja''', and '''Pongame oiltree'''.<ref name=USDA/><ref name="RFK8"/>

== Description == ''Pongamia pinnata'' is a legume tree that grows to about {{convert|15|-|25|m|ft|round=5|abbr=on}} in height with a large canopy which spreads equally wide and creates dense shade. It may be deciduous for short periods. It has a straight or crooked trunk, {{convert|50|-|80|cm|round=5|abbr=on}} in diameter, with grey-brown bark, which is smooth or vertically fissured. Its wood is white colored.<ref name=argent/> Branches are glabrous with pale stipulate scars. The imparipinnate leaves of the tree alternate and are short-stalked, rounded, or cuneate at the base; ovate or oblong along the length; obtuse-acuminate at the apex; and not toothed on the edges. They are a soft, shiny burgundy when young and mature to a glossy, deep green as the season progresses, with prominent veins underneath.<ref name=WorldAgro>{{cite web|url=http://www.worldagroforestry.org/treedb2/AFTPDFS/Pongamia_pinnata.pdf|title=Pongamia pinnata; Fabaceae - Papilionoideae; (L.) Pierre; pongam, karanj, karanga, kanji|author1=Orwa C. |author2=Mutua A. |author3=Kindt R. |author4=Jamnadass R. |author5=Simons A. |publisher=Agroforestry Database version 4.0 |year=2009 |access-date=2013-11-27}}</ref>

Flowering generally starts after 3–4 years with small clusters of white, purple, and pink flowers blossoming throughout the year.<ref name=giesen>Giesen, W., S. Wulffraat, M. Zierenand & L. Scholten (2007). [ftp://ftp.fao.org/docrep/fao/010/ag132e/ag132e00.pdf ''Mangrove Guidebook for Southeast Asia'']{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}}: 198-9. Bangkok :FAO and Wetlands International. ISBN 974-7946-85-8</ref> The raceme-like inflorescences bear two to four flowers that are strongly fragrant and grow to be {{convert|15|-|18|mm|abbr=on}} long. The calyx of the flowers is bell-shaped and truncated, while the corolla is a rounded ovate shape with basal auricles and often with a central blotch of green color.<ref name="RFK8"/><ref name=daff_AU>{{cite web|url=http://www.daff.qld.gov.au/__data/assets/pdf_file/0003/67575/IPA-Pongamia-Risk-Assessment.pdf|title=Weed Risk Assessment : Pongamia|publisher=Daff.qld.gov.au |access-date=2013-11-21}}</ref>

Croppings of indehiscent pods can occur by 4–6 years. The brown seed pods appear immediately after flowering, and mature in 10 to 11 months. The pods are thick-walled, smooth, somewhat flattened, and elliptical, but slightly curved with a short, curved point. The pods contain within them one or two bean-like brownish-red seeds, but because they do not split open naturally, the pods need to decompose before the seeds can germinate. The seeds are about {{convert|1.5|-|2.5|cm|abbr=on}} long with a brittle, oily coat, and are unpalatable in natural form to herbivores.<ref name=WorldAgro/><ref name=daff_AU/><ref name=argent>Argent, G., A. Saridan, EJF. Campbell, & P. Wilkie. "Leguminosae". ''Manual of The Larger and More Important Non-Dipterocarp Trees of Central Kalimantan, Indonesia.'' :366. Samarinda: Forest Research Institute.</ref>

''Pongamia pinnata'' is an outbreeding diploid legume tree, with a diploid chromosome number of 22.<ref name=daff_AU/> Root nodules are of the determinate type (as those on soybean and common bean) formed by the causative bacterium ''Bradyrhizobium''.

{{Gallery |mode=packed |Starr 080530-4642 Milletia pinnata.jpg|In Oahu, Hawaii |Pongamia pinnata.jpg|Inflorescence |Pollen grains of Pongamia pinnata.jpg|Pollen grains |PongamiaFlowersPodsSeeds (cropped).jpg|Fruits

|PongamiaPinnataGall.jpg|Leaves with galls |Pongam_pinnat_110716-15926_sntong.JPG |Pods, Gangga, North Lombok }}

== Taxonomy == The species was first described as ''Cytisus pinnatus'' by Carl Linnaeus in 1753. In 1898, Jean Baptiste Louis Pierre reclassified it as ''Pongamia pinnata''.<ref name="powo" /> In 1984, Robert Geesink concluded that species of ''Pongamia'' and ''Millettia'' were easily confused, and consolidated the ''Pongamia'' species into ''Millettia''. Subsequent studies revealed that ''Millettia pinnata'' was paraphyletic within ''Millettia'', and the species was reclassified as ''Pongamia pinnata'', the sole species in the revived genus ''Pongamia''.<ref name="Cooper">Wendy E. Cooper, Darren M. Crayn, Frank A. Zich, Rebecca E. Miller, Melissa Harrison, Lars Nauheimer "A review of Austrocallerya and Pongamia (Leguminosae subfamily Papilionoideae) in Australia, and the description of a new monotypic genus, Ibatiria," ''Australian Systematic Botany'', 32(4), 363-384, (29 August 2019) https://doi.org/10.1071/SB18039</ref>

== Distribution and habitat == The species is naturally distributed in tropical and temperate Asia, from India to Japan to Thailand to Malesia to north and northeastern Australia to some Pacific islands;<ref name=GRIN /><ref name="RFK8"/> It has been propagated and distributed further around the world in humid and subtropical environments from sea level to 1,360 m (Chingola, Zambia), although in the Himalayan foothills, it is not found above 600 m.<ref name="Winrock">[http://factnet.winrock.org/fnrm/factnet/factpub/FACTSH/P_pinnata.html Pongamia pinnata - a nitrogen fixing tree for oilseed] {{webarchive|url=https://web.archive.org/web/20160117130917/http://factnet.winrock.org/fnrm/factnet/factpub/FACTSH/P_pinnata.html |date=2016-01-17 }}</ref> Withstanding temperatures slightly below {{convert|0|°C|°F|abbr=on}} and up to about {{convert|50|°C|°F|abbr=on}} and annual rainfall of {{convert|500|–|2,500|mm|in|abbr=on}}, the tree grows wild on sandy and rocky soils, including oolitic limestone, and will grow in most soil types, even with its roots in salt water.<ref name="Purdue">{{cite web|url=http://www.hort.purdue.edu/newcrop/duke_energy/Pongamia_pinnata.html|title=Factsheet from New crops at Purdue University|publisher=Hort.purdue.edu |date=1998-01-08 |access-date=2013-09-28}}</ref>

The tree is well suited to intense heat and sunlight, and its dense network of lateral roots and its thick, long taproot make it drought tolerant. The dense shade it provides slows the evaporation of surface water and its root nodules promote nitrogen fixation, a symbiotic process by which gaseous nitrogen (N₂) from the air is converted into ammonium (NH₄⁺, a form of nitrogen available to the plant). ''M. pinnata ''is also a freshwater flooded forest species, as it can survive total submergence in water for few months continuously. ''M. pinnata'' trees are common in Tonlesap lake swamp forests in Cambodia.{{citation needed|date=April 2021}}

''P. pinnata'' is now broadly distributed across India, Asia, Africa, northern Australia, and the Pacific and Caribbean Islands and it has been cultivated and transported since the nineteenth century or earlier. As a result, some literature declares ''M. pinnata'' naturalized in Africa and certain parts of the United States, while its status as naturalized or native is uncertain in other regions.<ref>{{cite web |title=Pongamia Risk Assessment |url=https://www.daf.qld.gov.au/__data/assets/pdf_file/0003/67575/IPA-Pongamia-Risk-Assessment.pdf |access-date=22 July 2021}}</ref>

== Uses == ''Pongamia pinnata'' is well-adapted to arid zones, and has many traditional uses. It is often used for landscaping as a windbreak or for shade due to the large canopy and showy, fragrant flowers. The flowers are used by gardeners as compost for plants. The bark may be used to make twine or rope, and it also yields a black gum that has historically been used to treat wounds caused by poisonous fish. The wood is said to be beautifully grained, but splits easily when sawn, thus relegating it to firewood, posts, and tool handles.<ref name="Winrock" /> The tree's deep taproot and drought tolerance makes this tree ideal for controlling soil erosion and binding sand dunes.<ref name="Winrock" /> Rumphius writes the ''Malaparius'' (from Moluccan ''malapari''<ref name=heyne>Heyne, Karel (1987). ''Tumbuhan Berguna Indonesia'' '''2''': 1005. Jakarta: Badan Litbang Kehutanan, Departemen Kehutanan. Dutch version: [http://archive.org/stream/denuttigeplanten02heyn#page/306/mode/2up -1916- '''II''': 306.</ref>) bark can be used to neutralize eeltail catfish venom, Seram Timur and Banda peoples infuse it with garlic, massoy and clover to treat beri-beri.<ref name="rumpf">Rumpf, G.E. (1743). ''Herbarium Amboinense: plurimas conplectens arbores, frutices, ...'' [http://www.biodiversitylibrary.org/item/10353#page/301/mode/1up Pars '''III''': 183], [http://www.biodiversitylibrary.org/item/10353#page/303/mode/1up Tab. cxvii]. Amstelaedami :apud Franciscum Changuion, Joannem Catuffe, Hermannum Uttwerf. MDCCXLIII.</ref>

''Pongamia pinnata'' seeds generally contain oil (27-39%), protein (17-37%), starch (6-7%), crude fiber (5-7%), moisture (15-20%), and ash content (2-3%). Nearly half of the oil content of ''P. pinnata'' seeds is oleic acid.<ref>{{cite web |url=http://www.cilr.uq.edu.au/UserImages/File/factsheets/Pongamia%20Binder1.pdf |title=Pongamia Factsheet |access-date=2013-09-28 |archive-date=2013-05-01 |archive-url=https://web.archive.org/web/20130501195229/http://www.cilr.uq.edu.au/UserImages/File/factsheets/Pongamia%20Binder1.pdf |url-status=dead }}</ref> Oil made from the seeds, known as pongamia oil, has been used as lamp oil, in soapmaking, and as a lubricant. The oil has a high content of triglycerides. Its disagreeable taste and odor are due to bitter flavonoid constituents, including karanjin, pongamol, tannin, and karanjachromene.<ref name="Purdue" /> These compounds induce nausea and vomiting if ingested in its natural form. The fruits, sprouts and seeds are used in traditional medicine.<ref name="Purdue" /> Some studies have identified hiragonic acid in ''Pongamia pinnata'' seed oil.<ref>{{cite journal |last1=Shameel |first1=S. |last2=Usmanghani |first2=K. |last3=Ali |first3=M. S. |last4=Ahmad |first4=V. U. |title=Chemical constituents from the seeds of Pongamia pinnata (L.) Pierre |journal=Pakistan Journal of Pharmaceutical Sciences |date=January 1996 |volume=9 |issue=1 |pages=11–20 |pmid=16414771 |issn=1011-601X}}</ref>

It can be grown in rainwater harvesting ponds up to {{convert|6|m|ft|abbr=on}} in water depth without losing its greenery and remaining useful for biodiesel production.<ref>{{cite web |title=Rain water harvesting by fresh water flooded forests |url=https://www.scribd.com/doc/58789361/Rain-Water-Harvesting-by-Freshwater-Flooded-Forests |access-date=2013-09-28 |publisher=Scribd.com}}</ref><ref>{{Cite journal |last1=Degani |first1=Erika |last2=Prasad |first2=M. V. R. |last3=Paradkar |first3=Anant |last4=Pena |first4=Rodica |last5=Soltangheisi |first5=Amin |last6=Ullah |first6=Ihsan |last7=Warr |first7=Benjamin |last8=Tibbett |first8=Mark|display-authors=3 |date=2022-12-15 |title=A critical review of Pongamia pinnata multiple applications: From land remediation and carbon sequestration to socioeconomic benefits |journal=Journal of Environmental Management |language=en |volume=324 |article-number=116297 |doi=10.1016/j.jenvman.2022.116297 |pmid=36174475 |bibcode=2022JEnvM.32416297D |s2cid=252558634 |issn=0301-4797|doi-access=free }}</ref> Studies have shown seedlings with tolerance to salinity levels between 12 and 19 dS/m,<ref>{{Cite journal |last1=Tomar |first1=O. S. |last2=Gupta |first2=R. K. |date=1985-10-01 |title=Performance of some forest tree species in saline soils under shallow and saline water-table conditions |url=https://doi.org/10.1007/BF02181900 |journal=Plant and Soil |language=en |volume=87 |issue=3 |pages=329–335 |doi=10.1007/BF02181900 |bibcode=1985PlSoi..87..329T |s2cid=12335333 |issn=1573-5036|url-access=subscription }}</ref> with an ability to tolerate salinity stresses of 32.5 dS/m.<ref>{{Cite journal |last=Singh |first=K |date=1990 |title=Effect of soil salinity and sodicity on seedling growth and mineral composition of Pongamia pinnata and Araucaria cunninghamii |url=https://www.cabdirect.org/cabdirect/abstract/19910653629 |journal=Tropical Ecology |volume=31 |issue=2 |pages=124–130 |via=CAB Direct}}</ref> [[Image:plantationpre.jpg|thumb|250px|Pacific Renewable Energy trial plantation in Caboolture, Queensland]]

The seed oil has been found to be useful in diesel generators, and along with ''Jatropha'' and castor, it was explored in hundreds of projects throughout India and the third world as feedstock for biodiesel.<ref>{{cite journal|pmid=15939268|year=2005|last1=Karmee|first1=SK|last2=Chadha|first2=A|title=Preparation of biodiesel from crude oil of Pongamia pinnata|volume=96|issue=13|pages=1425–9|doi=10.1016/j.biortech.2004.12.011|journal=Bioresource Technology|bibcode=2005BiTec..96.1425K }}</ref> ''P. pinnata'' as a biofuel is commercially valuable to the rural populations of places such as India and Bangladesh, where the plant grows abundantly, because it can support the socioeconomic development of these areas.<ref>{{cite journal |last1=Halder |first1=P. K. |last2=Paul |first2=N. |last3=Beg |first3=M. R. A. |title=Prospect of Pongamia pinnata (Karanja) in Bangladesh: A Sustainable Source of Liquid Fuel |journal=Journal of Renewable Energy |date=18 December 2014 |volume=2014 |pages=1–12 |doi=10.1155/2014/647324 |doi-access=free }}</ref><ref>{{cite journal |last1=Kesari |first1=Vigya |last2=Rangan |first2=Latha |title=Development of Pongamia pinnata as an alternative biofuel crop — current status and scope of plantations in India |journal=Journal of Crop Science and Biotechnology |date=September 2010 |volume=13 |issue=3 |pages=127–137 |doi=10.1007/s12892-010-0064-1 |s2cid=2790680 |url=https://www.researchgate.net/publication/225255623 |access-date=23 July 2021}}</ref>{{Obsolete source|reason=cite is over 10 years old - is biofuel still seen as a good use?|date=August 2025}}

Research indicates potential use of ''P. pinnata'' as a food source for cattle, sheep, and poultry, as its byproduct contains up to 30% protein.<ref>{{cite journal|doi=10.1007/s12155-008-9003-0|title=Pongamia pinnata: An Untapped Resource for the Biofuels Industry of the Future|year=2008|last1=Scott|first1=Paul T.|last2=Pregelj|first2=Lisette|last3=Chen|first3=Ning|last4=Hadler|first4=Johanna S.|last5=Djordjevic|first5=Michael A.|last6=Gresshoff|first6=Peter M.|journal=BioEnergy Research|volume=1|issue=1 |page=2|bibcode=2008BioER...1....2S |s2cid=37994181}}</ref><ref>Heuzé V., Tran G., Delagarde R., Hassoun P., Bastianelli D., Lebas F., 2017. Karanja (Millettia pinnata). Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/636</ref> As adaptive uses are increasing, the tree is being planted in former citrus growing regions that have declined in Florida and California because of disease and climate change conditions.<ref>Frisaro, Freida, ''[https://apnews.com/article/pongamia-tree-citrus-florida-california-biofuel-protein-c9e781f0d1f7ea786b9748235c9dc320 Pongamia trees grow where citrus once flourished, offering renewable energy and plant-based protein]'', Associated Press, July 6, 2024</ref>

== References == {{Reflist}}

{{Bioenergy}} {{Taxonbar|from1=Q2717831|from2=Q24852568|from3=Q1973585}}

Category:Millettieae Category:Flora of the Indian subcontinent Category:Flora of Southeast Asia Category:Flora of Japan Category:Flora of Taiwan Category:Flora of Malesia Category:Flora of Papuasia Category:Flora of Melanesia Category:Flora of the Northern Territory Category:Flora of Queensland Category:Fabales of Asia Category:Fabales of Australia Category:Biofuel in India Category:Biodiesel feedstock sources Category:Sustainable agriculture Category:Plants described in 1753 Category:Botanical taxa named by Carl Linnaeus Category:Taxa named by Jean Baptiste Louis Pierre