Pontederia crassipes

{{Short description|Aquatic plant native to the Amazon basin}} {{hatnote|For other plants known as "water hyacinth", see ''Eichhornia''.}} {{use American English|date=January 2020}} {{use mdy dates|date=January 2020}} {{Speciesbox | name = Common water hyacinth | image = Eichhornia crassipes C.jpg | status = G5 | status_system = TNC | status_ref = <ref name=NS>{{cite NatureServe |id=2.133608 |title=''Eichhornia crassipes'' |access-date=9 May 2026}}</ref> | genus = Pontederia | species = crassipes | authority = Mart. | synonyms = * ''Eichhornia crassipes'' (Mart.) Solms * ''Eichhornia cordifolia'' Gand. * ''Eichhornia crassicaulis'' Schltdl. * ''Eichhornia speciosa'' Kunth * ''Heteranthera formosa'' Miq. * ''Piaropus crassipes'' (Mart.) Raf. * ''Piaropus mesomelas'' Raf. * ''Pontederia crassicaulis'' Schltdl. * ''Pontederia elongata'' Balf. |synonyms_ref = <ref name="POWO1" /> }}

'''''Pontederia crassipes''''' (formerly ''Eichhornia crassipes''), commonly known as '''common water hyacinth''', is an aquatic plant native to South America, naturalized throughout the world, and often invasive outside its native range.<ref name="POWO1">[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:310928-2 ''Pontederia crassipes'']. Kew Royal Botanic Gardens Plants of the World Online. Accessed April 19, 2022.</ref><ref name="POWO">[https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:1198589-2 ''Eichhornia crassipes'']. Kew Royal Botanic Gardens Plants of the World Online. Accessed April 19, 2022.</ref><ref name="PlntsBang">[http://www.floraofbangladesh.com/2016/06/kochuripana-water-hyacinth-eichhornia.html Kochuripana, Water hyacinth, Eichhornia crassipes ]. June 15, 2016. Flora of Bangladesh. Accessed April 19, 2022.</ref> It is the sole species of the subgenus ''Oshunae'' within the genus ''Pontederia''.<ref name=Pellegrini-etal2018/> Anecdotally, it is known as the "terror of Bengal" due to its invasive growth tendencies.

==Description== Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and subtropical South America.<ref>{{Cite journal |last1=Mahmood |first1=Qaisar |last2=Siddiqi |first2=M. Rehan |last3=Islam |first3=Ejaz ul |last4=Azim |first4=M. Rashid |last5=Zheng |first5=Ping |last6=Hayat |first6=Yousaf |date=2005-09-28 |title=Anatomical studies on water hyacinth ( Eichhornia crassipes (Mart.) Solms) under the influence of textile wastewater |url=http://www.zju.edu.cn/jzus/article.php?doi=10.1631/jzus.2005.B0991 |journal=Journal of Zhejiang University SCIENCE |language=en |volume=6B |issue=10 |pages=991–998 |doi=10.1631/jzus.2005.B0991 |doi-broken-date=May 5, 2026 |pmid=16187412 |pmc=1390441 |issn=1009-3095}}</ref> With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as {{convert|1|m|ft|0|abbr=on}} in height.<ref>{{Cite journal |last1=Khotsa |first1=Matlhatse Daisy |last2=Mkolo |first2=Nqobile Monate |last3=Motshudi |first3=Mmei Cheryl |last4=Mphephu |first4=Mukhethwa Micheal |last5=Makhafola |first5=Mmamudi Anna |last6=Naidoo |first6=Clarissa Marcelle |date=2025-08-12 |title=A Comprehensive Review of the Biology, Ecological Impacts, and Control Strategies of Eichhornia crassipes |journal=Diversity |language=en |volume=17 |issue=8 |page=564 |doi=10.3390/d17080564 |doi-access=free|bibcode=2025Diver..17..564K |issn=1424-2818}}</ref> The leaves are {{convert|10–20|cm|in|0|abbr=in|sp=us}} across on a stem, which is floating by means of buoyant bulb-like nodules at its base above the water surface. They have long, spongy, bulbous stalks. The feathery, freely hanging roots are purple-black. An erect stalk supports a single spike of 8–15 conspicuously attractive flowers, mostly lavender to pink in colour with six petals. When not in bloom, water hyacinth may be mistaken for frogbit (''Limnobium spongia''<ref>{{cite web |website=UF / IFAS Center for Aquatic and Invasive Plants |url=https://plant-directory.ifas.ufl.edu/plant-directory/limnobium-spongia/ |title=Limnobium spongia}}</ref>) or Amazon frogbit (''Limnobium laevigatum'').

One of the fastest-growing plants known, water hyacinth reproduces primarily by way of runners or stolons, which eventually form daughter plants. Each plant additionally can produce thousands of seeds each year, and these seeds can remain viable for more than 28 years.<ref>{{cite conference |last1=Sullivan |first1=Paul R |last2=Wood |first2=Rod |date=2012 |title=Water hyacinth (Eichhornia crassipes (Mart.) Solms) seed longevity and the implications for management |conference=18th Australasian Weeds Conference |location=Melbourne |url=https://www.cabi.org/isc/FullTextPDF/2012/20123367606.pdf}}</ref> Common water hyacinths are vigorous growers, and mats can double in size in one to two weeks.<ref name=weeds/> In terms of plant count rather than size, they are said to multiply by more than a hundredfold in number in a matter of 23 days.

In their native range, the flowers are pollinated by long-tongued bees.<ref>{{Cite journal |last1=Coetzee |first1=Julie A. |last2=Hill |first2=Martin P. |last3=Ruiz-Téllez |first3=Trinidad |last4=Starfinger |first4=Uwe |last5=Brunel |first5=Sarah |date=2017-10-02 |title=Monographs on invasive plants in Europe N° 2: Eichhornia crassipes (Mart.) Solms |url=https://www.tandfonline.com/doi/full/10.1080/23818107.2017.1381041 |journal=Botany Letters |language=en |volume=164 |issue=4 |pages=303–326 |doi=10.1080/23818107.2017.1381041 |bibcode=2017BotL..164..303C |issn=2381-8107}}</ref> These plants can reproduce both sexually and clonally. The invasiveness of the hyacinth is related to its ability to clone itself, and large patches are likely to all be part of the same genetic form.<ref>{{Cite journal |last1=Harun |first1=Irina |last2=Pushiri |first2=Hafizah |last3=Amirul-Aiman |first3=Ahmad Juhari |last4=Zulkeflee |first4=Zufarzaana |date=2021-08-06 |title=Invasive Water Hyacinth: Ecology, Impacts and Prospects for the Rural Economy |journal=Plants |language=en |volume=10 |issue=8 |page=1613 |doi=10.3390/plants10081613 |doi-access=free|issn=2223-7747 |pmc=8401593 |pmid=34451658 |bibcode=2021Plnts..10.1613H }}</ref>

Water hyacinth has three flower morphs and is termed "tristylous". The flower morphs are named for the length of their pistils: long (L), medium (M), and short (S).<ref>{{cite journal |last1=Rojas-Sandoval |first1=J. |last2=Acevedo-Rodríguez |first2=P. |title=''Eichhornia crassipes'' (water hyacinth) |url=https://www.cabi.org/isc/datasheet/20544 |publisher=CABI |website=Invasive Species Compendium |date=2013 |volume=CABI Compendium |article-number=20544 |doi=10.1079/cabicompendium.20544 |access-date=14 November 2017}}</ref> Tristylous populations are, however, limited to the native lowland South American range of water hyacinth; in the introduced range, the M-morph prevails, with the L-morph occurring occasionally and the S-morph absent altogether.<ref>Barrett, Spencer C.H. (1977) Tristyly in Eichhornia crassipes (Water Hyacinth). Biotropica, 9: 230–238</ref> This geographical distribution of the floral morphs indicates that founder events have played a prominent role in the species' worldwide spread.<ref>Barrett, Spencer C.H. (1989) Waterweed invasions. Scientific American, 260: 90–97.</ref>

==Habitat and ecology== Its habitat ranges from tropical desert to subtropical or warm, temperate desert to rainforest zones. The temperature tolerance of the water hyacinth is: * Its minimum growth temperature is {{convert |12|C|F}} * Its optimum growth temperature is {{convert |25|-|30|C|F}} * Its maximum growth temperature is {{convert |33|-|35|C|F}} Its pH tolerance is estimated at 5.0–7.5. Leaves are killed by frost and plants do not tolerate water temperatures more than {{convert |34|C|F}}. Water hyacinths do not grow where the average salinity is greater than 15% that of sea water (around 5 g salt per kg). In brackish water, its leaves show epinasty and chlorosis, and eventually die. Rafts of harvested water hyacinth have been floated to the sea, which kills it.<ref name = duke>{{harvnb|Duke|1983|loc=[https://hort.purdue.edu/newcrop/duke_energy/Eichornia_crassipes.html ''Eichhornia crassipes'' (Mart.) Solms]}}</ref>

''Azotobacter chroococcum'', a species of nitrogen-fixing bacteria, is probably concentrated around the bases of the petioles, but the bacteria do not fix nitrogen unless the plant is suffering extreme nitrogen deficiency.<ref name = matai>{{citation|last1=Matai |first1=S.|last2=Bagchi |first2=D.K. |title=Water hyacinth: a plant with prolific bioproductivity and photosynthesis |pages=144–148 |editor1=Gnanam, A. |editor2=Krishnaswamy, S. |editor3=Kahn, J.S. |work=Proceedings of the International Symposium on Biological Applications of Solar Energy, 1–5 December 1978 |publisher=MacMillan Co. of India, Madras |year=1980 |url=https://books.google.com/books?id=nWNBAAAAYAAJ&q=%22water+hyacinth%22}} apud {{harvp|Duke|1983}}.</ref>

Fresh plants contain prickly crystals.<ref name = duke/> This plant is reported to contain hydrogen cyanide, alkaloids, and triterpenoids, and may induce itching.<ref name = perry>''Medicinal plants of east and southeast Asia.'' By L.M Perry. 1980. MIT Press, Cambridge. Cited in {{harvp|Duke|1983}}.</ref> Plants sprayed with 2,4-dichlorophenoxyacetic acid (2,4-D) may accumulate lethal doses of nitrates<ref name = gohl>''Tropical feeds. Feed information summaries and nutritive values.'' By B. Gohl. 1981. FAO Animal Production and Health Series 12. FAO, Rome. Cited in {{harvp|Duke|1983}}.</ref> and other harmful elements in polluted environments.{{Citation needed|date=May 2021}}

== Invasive species == Water hyacinth grows and reproduces quickly, so it can cover large portions of ponds and lakes.<ref name=":02">{{cite web |last=Voiland |first=Adam |date=1 June 2016 |title=Seven Things You Didn't Know About Water Hyacinth |url=https://earthobservatory.nasa.gov/blogs/earthmatters/2016/06/01/seven-things-you-didnt-know-about-water-hyacinth/ |access-date=21 November 2017 |website=Earth Observatory}}</ref> It can easily coexist with other invasive plants and native plants in an area.<ref>{{cite journal | last1=Ghoussein | first1=Y. | last2=Abou Hamdan | first2=H. | last3=Fadel | first3=A. | last4=Coudreuse | first4=J. | last5=Nicolas | first5=H. | last6=Faour | first6=G. | last7=Haury | first7=J. | title=Biology and ecology of Pontederia crassipes in a Mediterranean river in Lebanon | journal=Aquatic Botany | date=2023 | volume=188 | article-number=103681 | doi=10.1016/j.aquabot.2023.103681 | bibcode=2023AqBot.18803681G | url=https://institut-agro-rennes-angers.hal.science/hal-04188106 }}</ref> Particularly vulnerable are bodies of water that have already been affected by human activities, such as artificial reservoirs or eutrophied lakes that receive large amounts of nutrients.<ref>{{Cite journal |last1=Coetzee |first1=Julie A. |last2=Hill |first2=Martin P. |date=2012-04-01 |title=The role of eutrophication in the biological control of water hyacinth, Eichhornia crassipes, in South Africa |journal=BioControl |language=en |volume=57 |issue=2 |pages=247–261 |doi=10.1007/s10526-011-9426-y |bibcode=2012BioCo..57..247C |s2cid=16415244 |issn=1573-8248}}</ref><ref>{{Cite journal |last1=Yu |first1=Haihao |last2=Dong |first2=Xianru |last3=Yu |first3=Dan |last4=Liu |first4=Chunhua |last5=Fan |first5=Shufeng |date=2019 |title=Effects of Eutrophication and Different Water Levels on Overwintering of Eichhornia crassipes at the Northern Margin of Its Distribution in China |journal=Frontiers in Plant Science |volume=10 |article-number=1261 |doi=10.3389/fpls.2019.01261 |issn=1664-462X |pmc=6788430 |pmid=31636651|doi-access=free |bibcode=2019FrPS...10.1261Y }}</ref> It outcompetes native aquatic plants, both floating and submerged.<ref name=":02" /><ref name=":12">{{cite web |title=Non-native Invasive Freshwater Plants — Water Hyacinth (Eichornia crassipes) — Technical Information |url=http://www.ecy.wa.gov/programs/wq/plants/weeds/aqua010.html |archive-url=https://web.archive.org/web/20171115000059/http://www.ecy.wa.gov/programs/wq/plants/weeds/aqua010.html |archive-date=2017-11-15 |access-date=21 November 2017 |website=Washington State Department of Ecology}}</ref> In 2011, Wu Fuqin et al.<ref>{{Cite journal |last1=Li |first1=Xuebao |last2=Wu |first2=Zhenbin |last3=He |first3=Guangyuan |date=May 1995 |title=Effects of low temperature and physiological age on superoxide dismutase in water hyacinth (Eichhornia crassipes Solms) |journal=Aquatic Botany |volume=50 |issue=2 |pages=193–200 |doi=10.1016/0304-3770(94)00417-k |bibcode=1995AqBot..50..193L |issn=0304-3770}}</ref> tracked the results of Yunnan Dianchi Lake and also showed that water hyacinth could affect the photosynthesis of phytoplankton, submerged plants, and algae by water environment quality and inhibit their growth. The decay process depletes dissolved oxygen in the water, often killing fish.<ref name=":02" />

Water hyacinth can absorb a large amount of harmful heavy metals and other substances. After death, it rots and sinks to the bottom of the water, causing secondary pollution to the water body, destroying the natural water quality, and may even affect the quality of residents' drinking water in severe cases. Water where water hyacinth grows heavily is often a breeding place for disease vectors (e.g. mosquitoes<ref name=":12" /> and snails<ref>{{cite journal |last1=Coles |first1=G.C. |last2=Kabatereine |first2=N.B. |date=June 2008 |title=Water hyacinth and the transmission of schistosomiasis |journal=Transactions of the Royal Society of Tropical Medicine and Hygiene |volume=102 |issue=6 |pages=619–620 |doi=10.1016/j.trstmh.2008.01.009 |pmid=18374376}}</ref>) and harmful pathogens, posing a potential threat to the health of local residents.<ref>{{Cite journal |last1=Kong |first1=Fanbin |last2=Xiong |first2=Kai |last3=Zhang |first3=Ning |date=2014-09-29 |title=Determinants of Farmers' Willingness to Pay and Its Level for Ecological Compensation of Poyang Lake Wetland, China: A Household-Level Survey |journal=Sustainability |volume=6 |issue=10 |pages=6714–6728 |doi=10.3390/su6106714 |issn=2071-1050 |doi-access=free |bibcode=2014Sust....6.6714K }}</ref> It is very critical to monitor areas quickly that are infested in order to efficiently reduce or control the growth of these species.<ref>{{cite journal | last1=Datta | first1=Aviraj | last2=Maharaj | first2=Savitri | last3=Prabhu | first3=G. Nagendra | last4=Bhowmik | first4=Deepayan | last5=Marino | first5=Armando | last6=Akbari | first6=Vahid | last7=Rupavatharam | first7=Srikanth | last8=Sujeetha | first8=J. Alice R. P. | last9=Anantrao | first9=Girish Gunjotikar | last10=Poduvattil | first10=Vidhu Kampurath | last11=Kumar | first11=Saurav | last12=Kleczkowski | first12=Adam | title=Monitoring the Spread of Water Hyacinth (Pontederia crassipes): Challenges and Future Developments | journal=Frontiers in Ecology and Evolution | date=2021 | volume=9 | article-number=631338 | doi=10.3389/fevo.2021.631338 | doi-access=free | bibcode=2021FrEEv...931338D }}</ref> Water hyacinth can also provide a food source for goldfish, keep water clean,<ref name="J. Todd, B. Josephson 19962">{{cite journal |last1=Todd |first1=J. |last2=Josephson |first2=B. |date=May 1996 |title=The design of living technologies for waste treatment |journal=Ecological Engineering |volume=6 |issue=1–3 |pages=109–136 |doi=10.1016/0925-8574(95)00054-2 |bibcode=1996EcEng...6..109T |s2cid=13068184}}</ref><ref>{{cite journal |last=Sheffield |first=C.W. |date=June 1967 |title=Water Hyacinth For Nutrient Removal |url=http://www.apms.org/japm/vol06/v6p27.pdf |journal=Journal of Aquatic Plant Management |volume=6 |pages=27–30 |access-date=31 July 2013 |archive-date=March 4, 2016 |archive-url=https://web.archive.org/web/20160304100111/http://www.apms.org/japm/vol06/v6p27.pdf }}</ref> and help with oxygenation.<ref>{{cite web |last=Hanson |first=Sarah |date=20 March 2013 |title=''Eichhornia crassipes'' – The 'Jekyll and Hyde' of the freshwater world |url=http://blogs.reading.ac.uk/tropical-biodiversity/2013/03/eichhornia-crassipes-the-jekyll-and-hyde-of-the-freshwater-world/ |access-date=21 November 2017 |website=Tropical Biodiversity}}</ref> Invertebrate species harboring with water hyacinth are dispersed as phytochores.<ref>{{cite journal |author=Volovnik S.V. |title=Phytochory – the dispersal of animals by terrestrial and aquatic plants |journal=Journal of Natural History |year=2025 |volume=59 |issue=21–24 | pages=1469–1539 |doi=10.1080/00222933.2025.2475536 |bibcode=2025JNatH..59.1469V |access-date=1 September 2025 |url=https://www.tandfonline.com/doi/abs/10.1080/00222933.2025.2475536}}</ref>

The invasion of water hyacinth also has socioeconomic consequences. Since water hyacinth is composed of up to 95% water, its evapotranspiration rate is high.{{cn|date=April 2026}} As such, small lakes that have been covered with the species can dry out and leave communities without adequate water or food supply. In some areas, dense mats of water hyacinth prevent the use of a waterway, leading to the loss of transportation (both human and cargo), as well as a loss of fishing possibilities.<ref>{{cite book |last=Twongo |first=T. |title=The Limnology, Climatology and Paleoclimatology of the East African Lakes |date=2019-08-13 |publisher=Routledge |isbn=978-0-203-74897-8 |pages=633–642 |chapter=Growing Impact of Water Hyacinth on Nearshore Environments on Lakes Victoria and Kyoga (East Africa) |doi=10.1201/9780203748978-35 |s2cid=202198793}}</ref><ref>{{Cite journal |last1=Villamagna |first1=A. M. |last2=Murphy |first2=B. R. |date=2010 |title=Ecological and socio-economic impacts of invasive water hyacinth (Eichhornia crassipes): a review |journal=Freshwater Biology |language=en |volume=55 |issue=2 |pages=282–298 |doi=10.1111/j.1365-2427.2009.02294.x |bibcode=2010FrBio..55..282V |issn=1365-2427}}</ref> Large sums of money are allocated to the removal of water hyacinth from the water bodies as well as figuring out how to destroy the remains harvested.<ref>{{Cite journal |last1=Wyk |first1=E. van |last2=Wilgen |first2=B. W. van |date=2002-01-01 |title=The cost of water hyacinth control in South Africa: a case study of three options |journal=African Journal of Aquatic Science |volume=27 |issue=2 |pages=141–149 |doi=10.2989/16085914.2002.9626585 |bibcode=2002AfJAS..27..141V |issn=1608-5914 |s2cid=218644199}}</ref><ref>{{Cite journal |last1=Chu |first1=Jian-jun |last2=Ding |first2=Yi |last3=Zhuang |first3=Qi-jia |date=2006-08-14 |title=Invasion and control of water hyacinth (Eichhornia crassipes) in China |journal=Journal of Zhejiang University Science B |language=en |volume=7 |issue=8 |pages=623–626 |doi=10.1631/jzus.2006.B0623 |pmid=16845715 |pmc=1533751 |issn=1673-1581}}</ref> Harvesting water hyacinth mechanically requires considerable effort. A million tons of fresh biomass would require 75 trucks with a capacity of 40 m3, per day, for 365 days to get rid of it.<ref>{{Cite book |title=Water Hyacinth |date=2017-08-09 |isbn=978-1-315-15180-9 |doi=10.1201/9781315151809}}</ref> The water hyacinth would then be transferred to a dumping site and allowed to decompose, which releases CO2, methane, and nitrogen oxides.<ref>{{Cite journal |last1=Sarika |first1=D. |last2=Singh |first2=Jiwan |last3=Prasad |first3=Ravi |last4=Vishan |first4=Isha |last5=Varma |first5=V. Sudharsan |last6=Kalamdhad |first6=Ajay S. |date=September 2014 |title=Study of physico-chemical and biochemical parameters during rotary drum composting of water hyacinth |journal=International Journal of Recycling of Organic Waste in Agriculture |language=en |volume=3 |issue=3 |page=9 |doi=10.1007/s40093-014-0063-1 |issn=2195-3228 |s2cid=86070957|doi-access=free |bibcode=2014IJROW...3....9S }}</ref>

Water hyacinth has been widely introduced in North America, Europe, Asia, Australia, Africa, and New Zealand.<ref>{{cite web |last=Gannon |first=Mike |date=15 January 2014 |title=Water Hyacinth – In and Out of Your Water Garden |url=http://fullserviceaquatics.com/aquatic-plants/water-hyacinth-in-and-out-of-your-water-garden/ |website=Full Service Aquatics}}</ref> In many areas, it has become an important and pernicious invasive species. In New Zealand, it is listed on the National Pest Plant Accord, which prevents it from being propagated, distributed, or sold. In large water areas such as Louisiana, the Kerala Backwaters in India, Tonlé Sap in Cambodia, and Lake Victoria, it has become a serious pest. The common water hyacinth has become an invasive plant species on Lake Victoria in Africa after it was introduced into the area in the 1980s.<ref>{{cite web |last=Chepkoech |first=Anita |date=7 February 2017 |title=Removal of Water Hyacinth Could Take Longer, Expert Says |url=http://www.nation.co.ke/counties/kisumu/removal-of-water-hyacinth-lake-victoria-could-take-longer/1954182-3804090-mw2c6z/index.html |website=Daily Nation}}</ref>

A 1.22 Gb/8 chromosome reference genome was assembled to study nuclear and chloroplast genomes between 10 water hyacinth lines from 3 continents.<ref name=":3">{{Cite journal |doi=10.1093/gigascience/giae006 |title=A reference genome of Commelinales provides insights into the commelinids evolution and global spread of water hyacinth ( ''Pontederia crassipes'' ) |date=2024 |last1=Huang |first1=Yujie |last2=Guo |first2=Longbiao |last3=Xie |first3=Lingjuan |last4=Shang |first4=Nianmin |last5=Wu |first5=Dongya |last6=Ye |first6=Chuyu |last7=Rudell |first7=Eduardo Carlos |last8=Okada |first8=Kazunori |last9=Zhu |first9=Qian-Hao |last10=Song |first10=Beng-Kah |last11=Cai |first11=Daguang |last12=Junior |first12=Aldo Merotto |last13=Bai |first13=Lianyang |last14=Fan |first14=Longjiang |journal=GigaScience |volume=13 |article-number=giae006 |pmid=38486346 |pmc=10938897 }}</ref> Results indicate the spread of a limited genotype of water hyacinth from South America, where it has the highest genetic diversity. The paper proposes the spread potentially originating from ships travelling from Itajaí Port on the Brazilian East Coast.<ref name=":3" /> However, genetic studies on samples from Bangladesh and Indonesia demonstrate different genotypes, potentially implicating multiple introduction vectors.<ref>{{Cite journal |last1=Zhang |first1=Yuan-Ye |last2=Zhang |first2=Da-Yong |last3=Barrett |first3=Spencer C. H. |date=May 2010 |title=Genetic uniformity characterizes the invasive spread of water hyacinth (''Eichhornia crassipes''), a clonal aquatic plant |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1365-294X.2010.04609.x |journal=Molecular Ecology |language=en |volume=19 |issue=9 |pages=1774–1786 |doi=10.1111/j.1365-294X.2010.04609.x|pmid=20529068 |bibcode=2010MolEc..19.1774Z |url-access=subscription }}</ref>

Further, the genomic study also revealed the adaptation in four key pathways; plant-pathogen interaction, plant-hormone signal transduction, photosynthesis and abiotic stress tolerance, which provide water hyacinth to expand its niche and compete with other native flora.<ref>{{cite journal |last1=Bisht |first1=Manohar S. |last2=Singh |first2=Mitali |last3=Chakraborty |first3=Abhisek |last4=Sharma |first4=Vineet K. |title=Genome of the most noxious weed water hyacinth (Eichhornia crassipes) provides insights into plant invasiveness and its translational potential |journal=iScience |date=2024 |volume=27 |issue=9 |article-number=110698 |doi=10.1016/j.isci.2024.110698 |doi-access=free |pmid=39262811 |pmc=11387899 |bibcode=2024iSci...27k0698B }}</ref>

=== United States ===

====Introduction into the U.S.====

Various accounts are given as to how the water hyacinth was introduced to the United States.{{Refn|group="lower-alpha"|Including indication that these were grown in nurseries and landscapes soon after the American Civil War (ended 1865).<ref>{{harvp|Penfound|Earle|1948|p=449}}: "some evidence... cultivated as greenhouse and landscape exotic shortly after the War between the States."</ref>}}

;{{small|1884 Exposition}} The claim that the water hyacinth was introduced to the U.S. in 1884 at the World's Fair in New Orleans, also known as the World Cotton Centennial,<ref name="mooallem2013"/> has been characterized as the "first authentic account",{{sfnp|Penfound|Earle|1948|p=449}} as well as "local legend".<ref name=douglas/>

;{{small|Alleged Japanese involvement}} At some point, a legend arose that the plants had been given away as a gift by a Japanese delegation at the fair.{{Refn|Claimed in Major James Brown (1941),<ref name=brown/> Vietmeyer (1975),{{sfnp|Vietmeyer|1975|p=65}} {{harvp|Wolverton|McDonald|1979|p=2}}, {{harvp|Barrett|2004|p=92}}, and Mooallem (2013)<ref name="mooallem2013"/> as delineated below.}} This claim is absent in a pertinent article published in a military engineer's trade journal dating to 1940,{{efn|Note that military engineers were tasked with the removal of water hyacinths in the South, as explained below.}}<ref name=wunderlich/> but appears in a piece penned in 1941 by the director of the wildlife and fisheries division at the Louisiana Department of Conservation, where the author writes, "the Japanese government maintained a Japanese building" at the fair, and the "Japanese staff imported from Venezuela considerable numbers of water hyacinth, which were given away as souvenirs".{{efn|{{harvp|Brown|1941}} also wrongly claims the species to be "a native to Japan", p. 9. Brown appears in a photograph on p. 12.}}<ref name=brown/> The claim has been repeated by later writers, with various shifts in the details. Thus National Academy of Sciences fellow Noel D. Vietmeyer (1975) wrote that "Japanese entrepreneurs" introduced the plant into the U.S., and the plants had been "collected from the Orinoco River in Venezuela."{{sfnp|Vietmeyer|1975|p=65}} This claim was echoed by a pair of NASA researchers ({{harvnb|Wolverton|McDonald|1979}}), who asserted that the souvenir plants were carelessly dumped in various waterways.<ref>{{harvp|Wolverton|McDonald|1979|p=2}}: " Japanese exhibitors coming to the 1884 Cotton States Exposition in New Orleans, Louisiana, brought along this aquatic plant because of its beautiful lavender flowers. They had collected the water hyacinths from the Orinoco River in Venezuela. These plants were given away at the exposition as souvenirs".</ref> Canadian biologist Spencer C. H. Barrett (2004) meanwhile favored the theory they were first cultivated in garden ponds, after which they multiplied and escaped to the environs.<ref>{{harvp|Barrett|2004|p=92}}: "..In that year water hyacinths imported from the lower Orinoco River in Venezuela were distributed as gifts by a Japanese delegation".</ref> The account gains different details as told by children's story-teller Carole Marsh (1992), who says "Japan gave away water hyacinth seeds" during the exposition,<ref name=marsh/> and another Southern raconteur, Gaspar J. "Buddy" Stall (1998), assured his readership that the Japanese gave each family a package of those seeds.<ref name=stall/>

;{{small|Other means of introduction}} One paper has also inquired into the role which catalog sales of seeds and plants may have played in the dissemination of invasive plants. ''P. crassipes'' was found to have been offered in the 1884 issue of Bordentown, New Jersey–based Edmund D. Sturtevant's ''Catalogue of Rare Water Lilies and Other Choice Aquatic Plants'',<ref name=mack/> and {{interlanguage link|Johann Nicolaus Haage (b. 1826){{!}}Haage & Schmidt|de|Johann Nicolaus Haage (Gärtner, 1826)}} of Germany has offered the plant since 1864 (when the firm was founded).<ref name=mack/> By 1895, it was offered by seed purveyors in the states of New Jersey, New York, California, and Florida.<ref>{{harvp|Mack|1991|pp=265–266, 262 (Table 1, ''Eicchornia crassipes'')}}</ref>{{Refn|group="lower-alpha"|It might be also noted that when the World's Fair returned to the U.S. in 1993 and was held in Chicago (World's Columbian Exposition), Edmund D. Sturtevant was there displaying his water lilies.<ref name=tricker/>}}

''Harper's Weekly'' magazine (1895) printed an anecdotal account stating that a certain man from New Orleans collected and brought home water hyacinths from Colombia, around 1892, and the plant proliferated in a matter of 2 years.<ref>{{citation|title=This Busy World |journal=Harper's Weekly |volume=39 |date=4 May 1895 |url=https://books.google.com/books?id=i4Y-AQAAMAAJ&pg=PA424}}</ref>

==== Infestation and control in the Southeast ====

As the hyacinths multiply into mats, they may be detrimental to some species of fish, and choke waterways for boating and shipping.{{sfnp|Penfound|Earle|1948|p=450}} This effect was already observed in the state of Louisiana by the turn of the 20th century.<ref name="mooallem2013"/>

The plant was introduced in Florida in 1890,<ref>{{harvnb|Webber|1897|p=11}}{{harvnb|Penfound|Earle|1948|p=449}}</ref> accumulating an estimated plant mass of 50 kg/m2<ref>{{cite journal |title=A Troublesome ′Water Weed′|journal=Popular Science Monthly |volume=LII |date=January 1898 |page=429 |url=https://www.biodiversitylibrary.org/page/1859110 |access-date=14 November 2017}}</ref> and clogging St. Johns River. In 1897 the government dispatched a task force of the United States Army Corps of Engineers to solve the water hyacinth problem plaguing Gulf states such as Florida and Louisiana.{{efn|The term "board of engineer officer" is used, but the biography from one of its members, in the West Point graduate roll, shows he was from the Army Corps of Engineers.<ref name=west-point/>}}{{sfn|Klorer|1909|p=43}}<ref name=west-point/>

In the early 20th century, the U.S. War Department (i.e., the Army Corps of Engineers) tested various means of eradicating the plants, including jet-streaming steam and hot water, applying various strong acids or petroleum followed by incineration.{{efn|The 1903 Experiment Report has "petroleum", whereas {{harvnb|Klorer|1909|p=443}} writes "Beaumont fuel oil".}} Spraying with saturated salt solution killed the plants but was considered prohibitively expensive. The engineers selected Harvesta brand herbicide, whose active ingredient was arsenic acid, as the optimal cost-effective tool for eradication.<ref>{{citation|title=Report on Experiments for Destruction of the Water Hyacinth in the Waters of Florida |work=Annual Report of the Department of War |volume=12 |number=4 |year=1903 |url=https://books.google.com/books?id=smX5_DEvoR4C&pg=PA2433 |page=2433}}</ref>{{sfn|Klorer|1909|pp=42–44}} This herbicide was used until 1905, when it was substituted with a different, white arsenic–based compound.{{sfn|Klorer|1909|pp=42–44}} An engineer charged with the spraying did not think the poison to be a matter of concern, stating that the crew of the spraying boat would routinely catch fish from their working areas and consume them.{{sfn|Klorer|1909|p=45}} However, spraying had little hope of completely eradicating the water hyacinth, due to the vastness of escaped colonies and the inaccessibility of some of the infested areas, and the engineer suggested that some biological means of control may be needed.{{sfn|Klorer|1909|p=47}}

In 1910 the New Foods Society suggested to import and release hippopotamus from Africa into the rivers and bayous of Louisiana to eat the water hyacinth and solve another serious problem at the time, the American meat crisis.<ref name="mooallem2013"/> Known as the American Hippo Bill, H.R. 23621 was introduced by Louisiana Congressman Robert Broussard and debated by the Agricultural Committee of the U.S. House of Representatives. The chief collaborators in the New Foods Society and proponents of Broussard's bill were Major Frederick Russell Burnham, the celebrated American Scout, and Captain Fritz Duquesne, a South African Scout who later became a notorious spy for Germany. Presenting before the Agricultural Committee, Burnham made the point that none of the animals that Americans ate (chickens, pigs, cattle, sheep, or lambs) were native to the U.S. and had all been imported by European settlers centuries before, so Americans should not hesitate to introduce hippopotamus and other large animals into the American diet. Duquesne, who was born and raised in South Africa, further noted that European settlers on that continent commonly included hippopotamus, ostrich, antelope, and other African wildlife in their diets and suffered no ill effects. The American Hippo Bill fell one vote short of passage.<ref name="mooallem2013"/>

Water hyacinths have also been introduced into waters inhabited by manatees in Florida, for the purpose of bioremediation (cf. §Phytoremediation below) of the waters that have become contaminated and fallen victim to algal blooming.<ref name=doughty&turner/> The manatees include the water hyacinth in their diet,<ref name=doughty&turner/> but it may not be the food of first choice for them.{{sfnp|Barrett|2004|p=96}}

==== Legality of sale and shipment in the United States ==== In 1956, ''E. crassipes'' was banned for sale or shipment in the United States, subject to a fine and/or imprisonment.<ref name="US-ban-law" /> This law was repealed by H.R. 133<ref>{{Cite web|last=Cuellar|first=Henry|date=2020-12-27|title=H.R.133 - 116th Congress (2019-2020): Consolidated Appropriations Act, 2021|url=https://www.congress.gov/bill/116th-congress/house-bill/133|access-date=2020-12-29|website=www.congress.gov}}</ref><ref name="US-ban-law-repealed" /> of the 116th Congress (2019–2021) on December 27, 2020.

=== Africa === {{See also|Water hyacinth in Lake Victoria}} thumb|Water hyacinth at Kisumu Port

The water hyacinth may have been introduced into Egypt in the late 18th to early 19th century during Muhammad Ali of Egypt's era, but was not recognized as an invasive threat until 1879.{{sfnp|Kitunda|2017|pp=xxiv, 6}}<ref>{{cite news |last=Hussein |first=Walaa |date=7 September 2016 |title=How this invasive flower is taking over the Nile |url=http://www.al-monitor.com/pulse/originals/2016/09/egypt-nile-water-flower-hyacinth-invasive-species.html |newspaper=Al-Monitor |location=CAIRO |url-access=subscription}}</ref> The invasion into Egypt is dated between 1879 and 1892 by Brij Gopal.{{sfn|Gopal|Sharma|1981}}<ref>Gopal; Junk; Davis (2000) [https://books.google.com/books?id=pj3wAAAAMAAJ&q=Egypt+%221879%22 '', Biodiversity in Wetlands'' '''2'''p. 109].</ref>

The plant (Afrikaans: ''waterhiasint''<ref name=stirton/>) arguably invaded South Africa in 1910,{{Refn|Dutoit. R., (1938). "Water hyacinth". ''Farming South Africa'' '''13''', 16–17, ''apud'' {{harvp|Ashton|Scott|Sten|Wells|1979|p=303}}<ref name=ashton/>}}{{sfn|Gopal|1987}}<ref>apud Gopal; Junk; Davis (2000) [https://books.google.com/books?id=pj3wAAAAMAAJ&q=%22hyacinth%22+%22South+Africa%22+%221910%22 '', Biodiversity in Wetlands'' '''2'''p. 109].</ref> although earlier dates have been claimed.{{Refn|The 1884 dating given by R. L. Kluge (1978)<ref>Kluge. R. L. (1978). Eichhornia crassipes. In Plant Invaders: Beautiful but Dangerous, edit. C. H. Stirton</ref> (also C. H. Stirton (1983)<ref name=stirton/>) is refuted by {{harvp|Ashton|Scott|Sten|Wells|1979|p=303}} as a mistake for the year it was introduced into the U. S., 1884 (year of the World's Fair in New Orleans, Louisiana). {{harvp|Kitunda|2017|pp=107–108}} cites Zimmermann, H. G. et al. (2007), that the plant was distributed at the 1904 St. Louis World's Fair, aka "Louisiana Purchase Exposition", and this was one possible route of transmission to South Africa in 1910.<ref name=wise&zimmermann/>}}{{Refn|group="lower-alpha"|The more ambitious by {{harvp|Kitunda|2017|p=xv}} dating to 1829 due to William Townsend Aiton of Kew Gardens does not pan out, since the pointed source, ''Curtis's Botanical Magazine'' (1829) merely states Aiton made the plant available then to Glasgow Botanic Gardens.<ref>Hooker, William Jackson (1829) "[https://www.biodiversitylibrary.org/item/14216#page/173/mode/1up #2932 Pontederia azurea. Large-flowered Pnotederia]", Curtis's Botanical Magazine, New Series '''3''' (=Vol. '''56''')</ref>}} A waterbody extensively threatened by water hyacinth is the Hartebeespoort Dam near Brits in North West Province.

The plant was introduced by Belgian colonists to Rwanda to beautify their holdings. It then advanced by natural means to Lake Victoria, where it was first sighted in 1988.<ref>{{cite news |language=de |url=http://www.spiegel.de/politik/ausland/0,1518,534060,00.html |title=Die grüne Pest |trans-title=The Green Pest |first=Thilo |last=Thielke |newspaper=Spiegel Online |date=2 September 2008 |access-date=2 September 2008}}</ref> There, without any natural enemies, it has become an ecological plague, suffocating the lake, diminishing the fish reservoir, and hurting the local economies. It impedes access to Kisumu and other harbors.

The water hyacinth has also appeared in Ethiopia, where it was first reported in 1965 at the Koka Reservoir and in the Awash River, where the Ethiopian Electric Light and Power Authority has managed to bring it under moderate control at considerable cost of human labor. Other infestations in Ethiopia include many bodies of water in the Gambela Region, the Blue Nile from Lake Tana into Sudan, and Lake Ellen near Alem Tena.<ref>{{cite journal |last=Rezene |first=F. |title=Water Hyacinth (''Eichhornia crassipes''): A Review of its Weed Status in Ethiopia |journal=Arem |volume=6 |date=2005 |pages=105–111}} Cited in {{cite journal |last1=Yirefu |first1=F. |last2=Tafesse |first2=A. |last3=Gebeyehu |first3=T. |last4=Tessema |first4=T. |title=Distribution, Impact and Management of Water Hyacinth at Wonji-Shewa Sugar Factory |url=http://www.eiar.gov.et/IAS-Publications/hyac1.pdf |journal=Ethiopian Journal of Weed Management |volume=1 |issue=1 |pages=41–52 |date=2007 |archive-url=https://web.archive.org/web/20140222153838/http://www.eiar.gov.et/IAS-Publications/hyac1.pdf |archive-date=2014-02-22}}</ref> By 2018, it has become a serious problem on Lake Tana in Ethiopia.

The water hyacinth is also present on the Shire River in the Liwonde National Park in Malawi.

===Asia=== thumb|Haldia Municipality Pool, a public water reservoir is being choked by growing water hyacinth population as in December 2019. [[File:The Eruption of Taal Volcano on it's 3rd day.jpg|thumb|Ash-covered blooming water hyacinth along the lakeshore in San Nicolas, Batangas, Philippines due to the eruption of Taal Volcano in the distance.]] thumb|Water hyacinth on a canal in Tien Giang province, Vietnam.

The water hyacinth was introduced to Bengal, because of its ornamental flowers and shapes of leaves, but became an invasive weed, draining oxygen from the water bodies and resulting in devastation of fish stocks.<ref>{{harvp|Gopal|Sharma|1981}}, apud Petr, T. (2000) ''[https://books.google.com/books?id=7tvoQ8-_PB4C&pg=PA84 Interactions Between Fish and Aquatic Macrophytes in Inland Waters: A Review]'', p. 84</ref> The water hyacinth was referred to as the "(beautiful) blue devil" in Bengal and "Bengal terror" elsewhere in India; it was called "German weed" (Bengali: ''Germani pana'') in Bangladesh out of belief the German Kaiser submarine mission<ref name="husain" /> was involved in introducing them at the outbreak of World War I. Concerted efforts were made to eradicate water hyacinths, which affected navigability in Bengal's rivers. The Bengal Water Hyacinth Act, 1936 prohibited the cultivation of the plants. By 1947, the problem was resolved, and navigability was restored to the rivers, although the plants still exist in wetlands.<ref>{{Cite Banglapedia|last=Pasha|first=Mostafa Kamal|article=Water Hyacinth}}</ref><ref>{{Cite web |last=Ashraful |first=Haque |date=2023-05-17 |title=Water hyacinth: A source of pollution until turned into a solution |url=https://www.tbsnews.net/features/panorama/water-hyacinth-source-pollution-until-turned-solution-633130 |access-date=2024-06-11 |website=The Business Standard |language=en}}</ref> Water hyacinths were called "Japanese trouble" in Sri Lanka because there was a rumor that the British had planted them to entice Japanese aircraft to land on the insecure pads.{{sfnp|Vietmeyer|1975|p=67}}{{sfnp|Monsod|1979|p=30}}

The plant entered Japan in 1884 for horticultural appreciation, according to conventional wisdom,{{sfnp|Kadono|2004|p=163}}{{sfnp|Ishii|Ninjo|Norinao|Maeda|2001|p=28}} but a researcher devoted to the study of the plant has discovered that ''ukiyo-e'' artist Utagawa Kunisada (or Utagawa Toyokuni III, d. 1865) produced a wood-block print featuring the water hyacinth, goldfish, and beautiful women, dated to 1855.{{sfnp|Ishii|Ninjo|Norinao|Maeda|2001|pp=29–30}} The plant is floated on the water surface of filled (glassware) fishbowls<ref name=kojien/> or glazed earthenware waterlily pots (hibachi pots serving as substitute).<ref name=kaneko/>

In the 1930s, water hyacinth was introduced into China as a feed, ornamental plant, and sewage-control plant, and it was widely planted in the south as an animal feed. Beginning in the 1980s, with the rapid development of China's inland industry, the eutrophication of inland waters has intensified. With the help of its efficient asexual reproduction and environmental adaptation mechanisms, water hyacinth began to spread widely in river basins. The hyacinths has blocked rivers and hindered water traffic. For example, many waterways in Zhejiang and other provinces have been blocked by the rapidly growing water hyacinth. In addition, a large number of water hyacinths floating in the water block sunlight from entering the water, and its decay consumes dissolved oxygen in the water, pollutes water quality, and can kill other aquatic plants.<ref>{{Cite journal |last1=Wu |first1=Hao |last2=Ding |first2=Jianqing |date=2019-06-12 |title=Global Change Sharpens the Double-Edged Sword Effect of Aquatic Alien Plants in China and Beyond |journal=Frontiers in Plant Science |volume=10 |article-number=787 |doi=10.3389/fpls.2019.00787 |doi-access=free|issn=1664-462X |pmc=6582753 |pmid=31249587 |bibcode=2019FrPS...10..787W }}</ref> The outbreak of water hyacinth has seriously affected the biodiversity of the local ecosystem and threatened the production, life, and health of community residents.<ref>{{Cite journal |last1=Lu |first1=Jianbo |last2=Wu |first2=Jianguo |last3=Fu |first3=Zhihui |last4=Zhu |first4=Lei |date=2007-11-26 |title=Water Hyacinth in China: A Sustainability Science-Based Management Framework |url=http://link.springer.com/10.1007/s00267-007-9003-4 |journal=Environmental Management |language=en |volume=40 |issue=6 |pages=823–830 |doi=10.1007/s00267-007-9003-4 |pmid=17768654 |bibcode=2007EnMan..40..823L |issn=0364-152X}}</ref>

===Europe=== In 2016, the European Union banned any sales of the water hyacinth in the EU.<ref>{{cite news |last1=Marks |first1=Simon |title=Dutch breeders hit back at EU's invasive alien species ban |url=https://www.politico.eu/article/dutch-breeders-hit-back-at-eus-invasive-alien-species-ban/ |access-date=10 September 2020 |work=Politico |date=14 December 2016}}</ref> The species features on the list of invasive alien species of Union concern.<ref>{{Cite web|title=List of Invasive Alien Species of Union concern - Environment - European Commission|url=https://ec.europa.eu/environment/nature/invasivealien/list/index_en.htm|access-date=2021-07-27|website=ec.europa.eu}}</ref> This means that not only the sales but also importation, cultivation, or intentional release into the environment are forbidden in the whole of the European Union.<ref>{{Cite web|title=REGULATION (EU) No 1143/2014 of the European parliament and of the council of 22 October 2014 on the prevention and management of the introduction and spread of invasive alien species|url=https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32014R1143&from=EN|url-status=live|archive-url=https://web.archive.org/web/20170303185733/http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32014R1143&from=EN |archive-date=March 3, 2017 }}</ref>

=== Oceania === In Papua New Guinea, water hyacinth blocks sunlight to other aquatic organisms, creates habitat for malaria-carrying mosquitoes, clogs waterways to the point that boats cannot get through, and reduces the quality of water for purposes such as cooking, washing, and drinking. People have lost income or even died due to being unable to travel to get food or medical care, or due to diseases from contaminated water or mosquitoes.<ref name=":2">{{Cite web |title=Biological control in Papua New Guinea {{!}} Global Education |url=https://globaleducation.edu.au/case-studies/biological-control-in-papua-new-guinea.html |access-date=2022-08-03 |website=globaleducation.edu.au |archive-date=October 18, 2022 |archive-url=https://web.archive.org/web/20221018015908/https://www.globaleducation.edu.au/case-studies/biological-control-in-papua-new-guinea.html }}</ref>

==Control== Control depends on the specific conditions of each affected location such as the extent of water hyacinth infestation, regional climate, and proximity to human and wildlife.<ref name=Villamagna>{{cite journal |last1=Villamagna |first1=Amy |last2=Murphy |first2=Brian |title=Ecological and socio-economic impacts of invasive water hyacinth (''Eichhornia crassipes''): a review |journal=Freshwater Biology |date=27 August 2009 |volume=55 |issue=2 |pages=282–298 |doi=10.1111/j.1365-2427.2009.02294.x|bibcode=2010FrBio..55..282V }}</ref>

=== Chemical control === Chemical control is the least used of the three controls of water hyacinth, because of its long-term effects on the environment and human health. The use of herbicides requires strict approval from governmental protection agencies and skilled technicians to handle and spray the affected areas. The use of chemical herbicides is only used in case of severe infiltration of water hyacinth.<ref name=California>{{cite web |title=Water Hyacinth |url=http://dbw.ca.gov/BoaterInfo/WaterHyacinth.aspx|website=California State Parks: Division of Boating and Waterways|publisher=State of California: Division of Boating and Waterways |archive-url=https://web.archive.org/web/20141114220334/http://dbw.ca.gov/BoaterInfo/WaterHyacinth.aspx |archive-date=2014-11-14}}</ref> However, the most successful use of herbicides is when it is used for smaller areas of infestation, because in larger areas, more mats of water hyacinths are likely to survive the herbicides and can fragment to further propagate a large area of water hyacinth mats. In addition, it is more cost-effective and less laborious than mechanical control, yet it can lead to environmental effects, as it can penetrate into the ground water system and can affect not only the hydrological cycle within an ecosystem, but also negatively affect the local water system and human health. Also of note, the use of herbicides is not strictly selective of water hyacinths; keystone species and vital organisms such as microalgae can perish from the toxins and can disrupt fragile food webs.<ref name="Villamagna"/>

The chemical regulation of water hyacinths can be done using common herbicides such as 2,4-D, glyphosate, and diquat. The herbicides are sprayed on the water hyacinth leaves and leads to direct changes to the physiology of the plant.<ref name=Jimenez>{{cite web |last1=Jiménez |first1=Maricela |title=Progress on water hyacinth (Eichhornia crassipes) management |url=http://www.fao.org/docrep/006/y5031e/y5031e0c.htm |publisher=Food and Agriculture Organization of the United Nations |access-date=4 November 2014}}</ref> The use of the herbicide known as 2,4-D leads to the death of water hyacinth through inhibition of cell growth of new tissue and cellular apoptosis.<ref>{{cite journal |last=Jiménez |first=VM |s2cid=2458933 |date=November 2005 |title=Involvement of plant hormones and plant growth regulators on in vitro somatic embryogenesis |journal=Plant Growth Regulation |volume=47 |issue=2–3 |pages=91–110 |doi=10.1007/s10725-005-3478-x |bibcode=2005PGroR..47...91J }}</ref> Almost a two-week period may be needed before mats of water hyacinth are destroyed with 2, 4-D. Between {{convert|75000|and|150000|acre}} of water hyacinth and alligator weed are treated annually in Louisiana.<ref name="Louisiana Agriculture">{{cite journal |last1=Sanders |first1=Dearl |last2=Jonhson |first2=Seth |last3=Kelso |first3=Bill |title=Invasive Aquatic Weeds in Louisiana |volume=53 |issue=4 |date=Fall 2010 |pages=34–37 |url=http://www.lsuagcenter.com/en/communications/publications/agmag/Archive/2010/fall/Invasive-Aquatic-Weeds-in-Louisiana.htm |journal=Louisiana Agriculture |access-date=13 October 2014}}</ref>

The herbicide known as diquat is a liquid bromide salt that can rapidly penetrate the leaves of the water hyacinth and lead to immediate inactivity of plant cells and cellular processes. The herbicide glyphosate has a lower toxicity than the other herbicides, so takes longer for the water hyacinth mats to be destroyed (about three weeks). The symptoms include steady wilting of the plants and a yellow discoloration of the plant leaves that eventually leads to plant decay.<ref name="California"/>

=== Physical control === Physical control is performed by land-based machines, such as bucket cranes, draglines, or boom, or by water-based machinery such as aquatic weed harvesters, dredges, or vegetation shredder.{{Citation needed|date=March 2026|reason=No sources about listed machines being used in control of water hyacinth}} Mechanical removal is seen as the best short-term solution to the proliferation of the plant.

[[File:Berky Mähsammelboot Typ 6520.jpg|thumb|right|alt=An aquatic weed harvester from the German manufacturer Berky collects the water plant via conveyor belt on a hold and can unload the material at the shore |An aquatic weed harvester collects the water plant via conveyor belt on a hold and can unload the material at the shore.]]

The spinning cutters of plant-harvesting machinery leave fragments of water hyacinth behind that can reproduce asexually.<ref name="Jimenez"/>

Harvested water hyacinth can pose a health risk to humans because of the plant's propensity for absorbing contaminants,<ref name=":1">{{Cite journal |last1=Huynh |first1=An The |last2=Chen |first2=Yi-Ching |last3=Tran |first3=Bich Ngoc Thi |date=October 2021 |title=A Small-Scale Study on Removal of Heavy Metals from Contaminated Water Using Water Hyacinth |journal=Processes |language=en |volume=9 |issue=10 |page=1802 |doi=10.3390/pr9101802 |issn=2227-9717 |doi-access=free}}</ref> and it is considered toxic to humans.<ref>{{cite journal |last1=Malik |first1=Anushree |title=Environmental challenge vis a vis opportunity: The case of water hyacinth |journal=Environment International |date=January 2007 |volume=33 |issue=1 |pages=122–138 |doi=10.1016/j.envint.2006.08.004 |pmid=17010439|bibcode=2007EnInt..33..122M }}</ref>

[[File:Megamelus scutellaris biocontrol.jpg|thumb|alt= In 2010, the insect ''Megamelus scutellaris'' was released by the Agricultural Research Service as a biological control for the invasive species ''Eichhornia crassipes'', more commonly known as water hyacinth.| In 2010, the insect ''Megamelus scutellaris'' was released by the Agricultural Research Service as a biological control for water hyacinth.<ref name=USDA2010>{{cite web |title=Scientists Release Biocontrol for Waterhyacinth |publisher=United States Department of Agriculture, Agricultural Research Service |url=https://www.ars.usda.gov/news-events/news/research-news/2010/scientists-release-biocontrol-for-waterhyacinth/}}</ref>]]

=== Biological control === As chemical and mechanical removals are often too expensive, polluting, and ineffective, researchers have turned to biological control agents to deal with water hyacinth. The effort began in the 1970s, when USDA researchers released into the United States three species of weevils known to feed on water hyacinth, ''Neochetina bruchi'', ''N. eichhorniae'', and the water hyacinth borer ''Sameodes albiguttalis''. The weevil species were introduced into the Gulf Coast states, such as Louisiana, Texas, and Florida, where thousands of acres were infested by water hyacinth. A decade later, a decrease was found in water hyacinth mats by as much as 33%, but because the lifecycle of the weevils is 90 days, the use of biological predation to efficiently suppress water hyacinth growth is limited.<ref name="Louisiana Agriculture" /> These organisms regulate water hyacinth by limiting its size, vegetative propagation, and seed production. They also carry microorganisms that can be pathological to the water hyacinth. These weevils eat stem tissue, which results in a loss of buoyancy for the plant, which will eventually sink.<ref name="Jimenez" /> Although meeting with only partial success, the weevils have since been released in many other countries.<ref name=":2" /><ref>{{Cite book |last=Roy. |first=Van Driesche |title=Biological control of invasive plants in the eastern United States |date=2002 |publisher=U.S. Dept. of Agriculture, Forest Service, Forest Health Technology Enterprise Team |pages=41–64 |oclc=51311198}}</ref> However, the most effective control method remains the control of excessive nutrients and prevention of the spread of this species.{{citation needed|date=October 2017}}

In May 2010, the USDA's Agricultural Research Service released ''Megamelus scutellaris'' as an additional biological control insect for the invasive water hyacinth species. ''M. scutellaris'' is a small planthopper insect native to Argentina. Researchers have been studying the effects of the biological control agent in extensive host-range studies since 2006 and concluded that the insect is highly host-specific and will not pose a threat to any other plant population other than the targeted water hyacinth. Researchers also hope that this biological control will be more resilient than existing biological controls and the herbicides that are already in place to combat the invasive water hyacinth.<ref name=USDA2010/> Another insect being considered as a biological control agent is the semiaquatic grasshopper ''Cornops aquaticum''. This insect is specific to the water hyacinth and its family, and besides feeding on the plant, it introduces a secondary pathogenic infestation. This grasshopper has been introduced into South Africa in controlled trials.<ref name=amedegnato&devriese/>

The Rhodes University Centre for Biological Control is rearing ''M. scutellaris'' and the water hyacinth weevils ''N. eichhorniae'' and ''N. bruchi'' en masse for biological control at dams in South Africa, including the Hartbeespoort Dam.<ref name="Sisonke">{{cite web | title=Sisonke | website=Centre for Biological Control - Rhodes University | date=2014-09-17 | url=http://www.ru.ac.za/centreforbiologicalcontrol/communityengagement/sisonke/about/ | access-date=2020-11-11}}</ref><ref>{{Cite web|date=2011-07-21|title=CBC releases status and future expectations for its Hartbeespoort Dam water hyacinth project|url=https://www.ru.ac.za/latestnews/cbcreleasesstatusandfutureexpectationsforitshartbeespoortdamwaterhyac.html|access-date=2022-02-13|website=www.ru.ac.za|language=en-US}}</ref> The moth ''Niphograpta albiguttalis'' (Warren) (Lepidoptera: Pyralidae) has been introduced to North America, Africa, and Australia. Larvae of this moth bore in the stems and flower buds of water hyacinth.<ref>{{Cite web |title=Species ''Niphograpta albiguttalis'' - Water Hyacinth Moth - Hodges#5149 |url=https://bugguide.net/node/view/49440 |access-date=2022-08-04 |website=bugguide.net}}</ref>

== Uses ==

=== Bioenergy === Due to its high growth rate, ''Pontederia crassipes'' is an excellent source of biomass. {{convert|1|ha|spell=In}} of standing crop produces more than {{convert|70000|m3/ha|ft3/acre|abbr=on}} of biogas (70% {{chem|C|H|4}}, 30% {{chem|C|O|2}}).<ref name = nas>{{cite book |author=National Research Council |title=Making Aquatic Weeds Useful: Some Perspectives for Developing Countries |publisher=The National Academies Press |location=Washington, DC |date=1976 |url=https://www.nap.edu/catalog/19948/making-aquatic-weeds-useful-some-perspectives-for-developing-countries |doi=10.17226/19948 |bibcode=1976nap..book19948N |access-date=15 November 2017|isbn=978-0-309-33457-0}}</ref> According to Curtis and Duke, {{convert|1|kg|lb|spell=in|abbr=on}} of dry matter can yield {{convert|370|L|ft3|abbr=out}} of biogas, giving a heating value of {{convert|22000|kJ/m3|Btu/ft3|abbr=on}} compared to pure methane (895 Btu/ft3)<ref name = curtis>Curtis, C.R.; Duke., J.A.(1982) ''An assessment of land biomass and energy potential for the Republic of Panama'', vol. 3. Institute of Energy Conversion. Univ. Delaware. apud {{harvp|Duke|1983}}.</ref>

Wolverton and McDonald report approximately {{convert|0.2|m3/kg|ft3/lb|sigfig=1|abbr=on}} methane,{{Refn|group="lower-alpha"|i.e., 200 liters out of the "350 to 411 liters of biogas per kg dry weight of water hyacinths (5.7 to 6.6 scf per dry lb)" reported by this team with Barlow.<ref>{{citation|last1=Wolverton |first1=B.C. |last2=Barlow |first2=R.M. |last3=McDonald |first3=R.C. |title=17. Application of Vascular Aquatic Plants for Pollution Removal, Energy, and Food Production in a Biological System |work=Biological Control of Water Pollution |editor-last=Tourbier |editor-first=J. |editor-last2=Pierson |editor-first2=R. W. Jr. |publisher= University of Pennsylvania Press |year=1976|pages=141–149}}, apud {{harvp|Wolverton|McDonald|1979|p=7}}</ref>}} indicating biomass requirements of {{convert|350|t/ha|ST/acre|abbr=on}} to attain the {{convert|70000|m3/ha |ft3/acre|abbr=on}} yield projected by the National Academy of Sciences (Washington).<ref name = wolv>Wolverton, B.C.; McDonald, R.C. (1981) "Energy from vascular plant wastewater treatment systems – Eichhornia crassipes, Spirodela lemna, Hydrocotyle ranunculoides, Pueraria lobata, biomass harvested for fuel production", ''Economic Botany'' '''35''' (2), pp. 224–232, {{doi|10.1007/BF02858689}}, apud {{harvp|Duke|1983}}.</ref> Ueki and Kobayashi mention more than {{convert|200|t/ha|ST/acre|sigfig=1|abbr=on}} per year.<ref name = ueki>Cultivation of new biomass resources. By K. Ueki and T. Kobayashi. 1981. Energy Develop. in Japan. 3(3):285–300. Cited in {{harvp|Duke|1983}}.</ref> Reddy and Tucker found an experimental maximum of more than {{convert|1/2|t/ha|ST/acre|frac=4}} per day.<ref name = reddy>''Productivity and nutrient uptake of water hyacinth Eichhornia crassipes''. By K.R. Reddy and J.C. Tucker. 1983. 1. Effect of nitrogenous source. Econ. Bot. 37(2):237–247. Cited in {{harvp|Duke|1983}}.</ref>

Bengali farmers collect and pile up these plants to dry at the onset of the cold season; they then use the dry water hyacinths as fuel. The ashes are used as fertilizer. In India, {{convert|1|t|ST|spell=in}} of dried water hyacinth yields about 50 liters ethanol and 200 kg residual fiber (7,700 Btu). Bacterial fermentation of {{convert|1|t|ST|spell=in}} yields 26,500 ft3 gas (600 Btu) with 51.6% methane ({{chem|C|H|4}}), 25.4% hydrogen ({{chem|H|2}}), 22.1% carbon dioxide ({{chem|C|O|2}}), and 1.2% oxygen ({{chem|O|2}}). Gasification of {{convert|1|t|ST|spell=in}} dry matter by air and steam at high temperatures ({{convert|800|C|F|-2|disp=or}}) gives about 40,000 ft3 (1,100 m3) natural gas (143 Btu/ft3) containing 16.6% {{chem|H|2}}, 4.8% {{chem|C|H|4}}, 21.7% {{chem|C|O}} (carbon monoxide), 4.1% {{chem|C|O|2}}, and 52.8% {{chem|N|2}} (nitrogen). The high moisture content of water hyacinth adds to handling costs and limits commercial use.<ref name = wolv/><ref name = csir>''The wealth of India.'' By C.S.I.R. (Council of Scientific and Industrial Research). 1948–1976. 11 vols. New Delhi. Cited in {{harvp|Duke|1983}}.</ref> A continuous, hydroponic production system would be more efficient than conventional batch operation.<ref name = duke/><ref name = ben>Benemann, J.R. (1981) "Energy from fresh and brackish water aquatic plants", pp. 99–121. In: Klass, D.L. (ed.), Biomass as a non-fossil fuel source. ACS Symposium Series 144. ACS. Washington. Cited in {{harvp|Duke|1983}}.</ref>

The labor involved in harvesting water hyacinth can be reduced by locating collection sites and processors on impoundments that take advantage of prevailing winds. The harvested biomass can be converted to ethanol, biogas, hydrogen, gaseous nitrogen, and/or fertilizer.<ref name=":0">{{Cite web |title=State of the art research on sustainable use of water hyacinth: A bibliometric and text mining analysis |url=https://scholar.google.com/citations?view_op=view_citation&hl=en&user=PRh78IkAAAAJ&citation_for_view=PRh78IkAAAAJ:UeHWp8X0CEIC |access-date=2022-04-14 |website=scholar.google.com}}x</ref> The byproduct water can be used to irrigate nearby cropland.<ref name = duke/>

=== Phytoremediation, waste water treatment === Water hyacinth could be used to remove arsenic from contaminated tube well water in Bangladesh.<ref>Misbahuddin, M.; Fariduddin, A.T.M. (2002). "Water Hyacinth Removes Arsenic from Arsenic-Contaminated Drinking Water". Archives of Environmental Health. 57: 516- 518.</ref>

Water hyacinth is observed to enhance nitrification in wastewater treatment cells. The root zones host bacterial communities.<ref name="J. Todd, B. Josephson 19962" />

Water hyacinth is a common fodder plant in the third world especially Africa though excessive use can be toxic. It is high in protein (nitrogen) and trace minerals.

Water hyacinth is reported for its efficiency to remove about 60–80% nitrogen.<ref>Fox, LJ; Struik, PC; Appleton, BL; Rule, JH; et al. (2008) Nitrogen phytoremediation by water hyacinth (''Eichhornia crassipes'' (Mart.) Solms). Water Air Soil Pollut 194:199–207</ref> and about 69% of potassium from water.<ref>Zhou, W; Zhu, D; Tan, L; Liao, S; Hu, H; David, H; et al. (2007) Extraction and retrieval of potassium from water hyacinth (''Eichhornia crassipes''). Biores Tech 98:226–231</ref> The roots of water hyacinth were found to remove particulate matter and nitrogen in a natural shallow eutrophicated wetland.<ref>Billore, SK; Bharadio, R; Kumar, A; et al. (1998) Potential removal of particulate matter and nitrogen through roots of water hyacinth in a tropical natural wetland. Curr Sci 74:154–156</ref><ref>{{Cite book |author1=Ansari, Abid |author2=Gill, Sarvajeet |author3=Khan, Fareed |author4=Ghauri, Naeem |title=Eutrophication: Causes, Consequences and Control |chapter=Phytoremediation Systems for the Recovery of Nutrients from Eutrophic Waters |date=2014 |volume=2 |pages=239–248 |url=https://www.researchgate.net/publication/260094644 |doi=10.1007/978-94-007-7814-6_17|isbn=978-94-007-7813-9}}</ref>

The plant is tolerant of, and has a high capacity for, the uptake of heavy metals, including cadmium, chromium, cobalt, nickel, lead, and mercury, which could make it suitable for the biocleaning of industrial wastewater.<ref name=":1" /><ref name="ppbc3">{{cite journal |last=Upadhyay |first=Alka R. |author2=B. D. Tripathi |year=2007 |title=Principle and Process of Biofiltration of Cd, Cr, Co, Ni & Pb from Tropical Opencast Coalmine Effluent |journal=Water, Air, & Soil Pollution |publisher=Springer |volume=180 |issue=1–4 |pages=213–223 |bibcode=2007WASP..180..213U |doi=10.1007/s11270-006-9264-1 |s2cid=97353113}}</ref><ref name="ctbe3">{{cite journal |last1=Abou-Shanab |first1=R. A. I. |last2=Angle |first2=JS |last3=Van Berkum |first3=P |display-authors=etal |year=2007 |title=Chromate-Tolerant Bacteria for Enhanced Metal Uptake by ''Eichhornia crassipes'' (MART.) |url=https://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=8357&content=PDF |journal=International Journal of Phytoremediation |volume=9 |issue=2 |pages=91–105 |doi=10.1080/15226510701232708 |pmid=18246718 |bibcode=2007IJPhy...9...91A |s2cid=21893402|url-access=subscription }}{{dead link|date=June 2025|bot=medic}}{{cbignore|bot=medic}}</ref><ref name="nmrc3">{{cite journal |last1=Maine |first1=M.A. |last2=Sune |first2=N |last3=Hadad |first3=H |last4=Sanchez |first4=G |last5=Bonetto |first5=C |display-authors=etal |year=2006 |title=Nutrient and metal removal in a constructed wetland for wastewater treatment from a metallurgic industry |journal=Ecological Engineering |publisher=Elsevier |volume=26 |issue=4 |pages=341–347 |doi=10.1016/j.ecoleng.2005.12.004|bibcode=2006EcEng..26..341M }}</ref><ref name="muaf3">{{cite journal |last1=Skinner |first1=Kathleen |last2=Wright |first2=N |last3=Porter-Goff |first3=E |display-authors=etal |year=2007 |title=Mercury uptake and accumulation by four species of aquatic plants |journal=Environmental Pollution |publisher=Elsevier |volume=145 |issue=1 |pages=234–237 |doi=10.1016/j.envpol.2006.03.017 |pmid=16781033|bibcode=2007EPoll.145..234S }}</ref><ref>{{cite book |last1=Niering |first1=William A. |title=The Audubon Society Field Guide to North American Wildflowers, Eastern Region |last2=Olmstead |first2=Nancy C. |publisher=Knopf |year=1985 |isbn=0-394-50432-1 |page=711 |author-link1=William Niering |orig-date=1979}}</ref>

The roots of ''Pontederia crassipes'' naturally absorb some organic compounds believed to be carcinogenic, in concentrations 10,000 times that in the surrounding water.<ref name = biosci>{{cite journal |title=UNKNOWN |department=Biology Briefs |journal=BioScience |volume=26 |issue=3 |page=224 |date=March 1976 |doi=10.2307/1297259|jstor=1297259}}</ref> Water hyacinths can be cultivated for waste water treatment (especially dairy waste water).<ref name = duke/>{{failed verification|date=July 2017}}

In addition to heavy metals, ''Pontederia crassipes'' can also remove other toxins, such as cyanide, which is environmentally beneficial in areas that have endured gold-mining operations.<ref name="cpwh3">{{cite journal |last1=Ebel |first1=Mathias |last2=Evangelou |first2=MW |last3=Schaeffer |first3=A |display-authors=etal |year=2007 |title=Cyanide phytoremediation by water hyacinths (''Eichhornia crassipes'') |journal=Chemosphere |publisher=Elsevier |volume=66 |issue=5 |pages=816–823 |bibcode=2007Chmsp..66..816E |doi=10.1016/j.chemosphere.2006.06.041 |pmid=16870228}}</ref>

Water hyacinth can take in and degrade ethion, a phosphorus pesticide.<ref>{{Cite journal |last1=XIA |first1=H |last2=MA |first2=X |date=May 2006 |title=Phytoremediation of ethion by water hyacinth (Eichhornia crassipes) from water |journal=Bioresource Technology |volume=97 |issue=8 |pages=1050–1054 |doi=10.1016/j.biortech.2005.04.039 |issn=0960-8524 |pmid=15982870|bibcode=2006BiTec..97.1050X }}</ref>

=== Agriculture ===

Water hyacinth is used as an organic fertilizer<ref name=aguilo-et-al/> and as animal feed<ref name=aguilo-et-al/> and silage for cattle, sheep, geese, pigs, and other livestock.<ref name="Yan-et-al-2016">{{cite journal | last1=Yan | first1=Shao-Hua | last2=Song | first2=Wei | last3=Guo | first3=Jun-Yao | title=Advances in management and utilization of invasive water hyacinth (''Eichhornia crassipes'') in aquatic ecosystems – a review | journal=Critical Reviews in Biotechnology | publisher=Taylor & Francis | volume=37 | issue=2 | date=2016-01-26 | issn=0738-8551 | doi=10.3109/07388551.2015.1132406 | pages=218–228 | s2cid=26481942 | pmid=26810214}}</ref>

In Bengal, India the ''kachuri-pana'' has been used primarily for fertilizer, compost or mulch, and secondarily as fodder for livestock and fish.<ref name=datta&baneriee/> In Bangladesh, farmers in the southwestern region cultivate vegetables on "floating gardens" usually with a bamboo-built frame base, with dried mass of water hyacinth covered in soil as bedding as a large portion of cultivable land goes under water for months during monsoon in this low-lying region. This method is also known as ''dhap chash'' and ''vasoman chash''.<ref name=habiba&shaw/>

In Kenya, East Africa, it has been used experimentally as organic fertilizer, although there is controversy stemming from the high alkaline pH value.<ref>{{cite web |title=Eichhornia crassipes |url=http://www.iucngisd.org/gisd/species.php?sc=70 |website=Global Invasive Species Database}}</ref>

===Other uses=== In various places in the world, the plant is used for making furniture, handbags, baskets, rope, and household goods/interior products (lampshades, picture frames) by businesses launched by NGOs and entrepreneurs.<ref name=aguilo-et-al>{{cite web |first1=Patricia |last1=Aguilo |first2=Amanda |last2=L'Esperance |first3=Elizabeth |last3=Mbau |first4=Phillip |last4=Palmer |first5=Asmita |last5=Patel |first6=Tim |last6=Sparkman |date=10 May 2007 |url=http://www.sipa.columbia.edu/academics/concentrations/epd/documents/2006-7/MCI%20-%20Investment%20Opportunities%20in%20Kisumu,%20Kenya.pdf |title=Attracting Investment to Kisumu: Opportunities and Challenges |page=78 |publisher=Columbia University |archive-url=https://web.archive.org/web/20120916072726/http://www.sipa.columbia.edu/academics/concentrations/epd/documents/2006-7/MCI%20-%20Investment%20Opportunities%20in%20Kisumu,%20Kenya.pdf |archive-date=2012-09-16}}</ref><ref name=doughty&turner/>

====Woven products==== American-Nigerian Achenyo Idachaba has won an award for showing how this plant can be exploited for profit as woven products in Nigeria.<ref>{{cite web|last=Idachaba |first=Achenyo |author-link=Achenyo Idachaba |title=How I turned a deadly plant into a thriving business |url=https://www.ted.com/talks/achenyo_idachaba_how_i_turned_a_deadly_plant_into_a_thriving_business?language=en |website=TED |date=May 2015}}</ref>

====Paper==== Though a study found water hyacinths of limited use for paper production,<ref>{{cite journal |url=http://www.apms.org/japm/vol12/v12p90.pdf |first1=W.J. |last1=Nolad |first2=D.W. |last2=Kirmse |title=The Papermaking Properties of Waterhyacinth |journal=Journal of Aquatic Plant Management |volume=12 |date=May 1974 |pages=90–97 |archive-date=August 31, 2021 |access-date=November 13, 2012 |archive-url=https://web.archive.org/web/20210831193840/http://www.apms.org/japm/vol12/v12p90.pdf }}</ref> they are nonetheless used on a small scale. Goswami pointed out in his article that water hyacinth has the potential to make tough and strong paper. He found that adding water hyacinth pulp to the raw material of bamboo pulp for anti-grease paper can increase the physical strength of paper.

====Edibility==== The plant is used as a carotene-rich table vegetable in Taiwan. Javanese sometimes cook and eat the green parts and inflorescence.<ref name = duke/> Vietnamese also cook the plant and sometimes add its young leaves and flower to their salads.

====Potential as bioherbicidal agent==== Water hyacinth leaf extract has been shown to exhibit phytotoxicity against another invasive weed ''Mimosa pigra''. The extract inhibited the germination of ''M. pigra'' seeds in addition to suppressing the root growth of the seedlings. Biochemical data suggested that the inhibitory effects may be mediated by enhanced hydrogen peroxide production, inhibition of soluble peroxidase activity, and stimulation of cell wall-bound peroxidase activity in the root tissues of ''M. pigra''.<ref>{{cite journal |last1=Chai |first1=TT |last2=Ngoi |first2=JC |last3=Wong |first3=FC |date=2013 |url=https://www.researchgate.net/publication/259358378 |title=Herbicidal potential of ''Eichhornia crassipes'' leaf extract against ''Mimosa pigra'' and ''Vigna radiata'' |journal=International Journal of Agriculture and Biology |volume=15 |issue=5 |pages=835‒842}}</ref>

====Bioplastics==== In Kenya, biodegradable plastics developed from dried water hyacinths are commercialized as food wrappers, straws, and party plates.<ref>{{Cite web|last=Maina|first=Margaret |date=2024-04-09 |title=Turning invasive hyacinth into eco-friendly plastic alternatives |url=https://nation.africa/kenya/health/turning-invasive-hyacinth-into-eco-friendly-plastic-alternatives-4584206 |access-date=2026-02-12 |website=Daily Nation |language=en}}</ref>

==Gallery== <gallery mode="packed" heights="135px"> File:Water_hyacinth.jpg|alt=Floating plant File:IMG 2365.jpg|alt=Flowers File:Eichhornia crassipes A.jpg|alt=Close-up of flowers File:Eichhornia crassipes-water hyacinth.jpg|alt=Large infested pond File:Eichhornia_Crassipes.jpg|Inflated petiole File:Water hyacinth in a field.jpg|A field full of Water hyacinth. File:Eichhornia crassipes field at Langkawi.jpg|Huge swamp field|alt=Huge infested swamp field </gallery>

==Explanatory notes== {{notelist}}

==References== {{Reflist|refs= <ref name="Pellegrini-etal2018">{{cite journal |author1=Pellegrini, M. O. O. |author2=Horn, C. N. |author3=Alemida, R. F. |name-list-style=amp | year = 2018 | title = Total evidence phylogeny of Pontederiaceae (Commelinales) sheds light on the necessity of its recircumscription and synopsis of Pontederia L. | journal = PhytoKeys |issue=108 | pages = 25–83 | url = https://phytokeys.pensoft.net/article/27652/ | doi = 10.3897/phytokeys.108.27652 |pmid=30275733 |pmc=6160854 | doi-access = free |bibcode=2018PhytK.108...25P }}</ref>

<ref name=amedegnato&devriese>{{citation|last1=Amédégnato |first1=Christiane |author-link1= |last2=Devriese |first2=Hendrik |author-link2= |title=Global diversity of true and pygmy grasshoppers (Acridomorpha, Orthoptera) in freshwater|editor1=Balian, E.V. |editor2=Lévêque, C. |editor3=Segers, H. |editor4=Martens, K. |work=Freshwater Animal Diversity Assessment|url=https://books.google.com/books?id=Dw4H6DBHnAgC&pg=PA542 |year=2008 |publisher=Springer Science & Business Media |isbn=978-1-4020-8259-7 |page=542}}. Reprinted from ''Hydrobiologia'', '''595''' (2008), {{doi|10.1007/s10750-007-9132-z}}.</ref>

<ref name=ashton>{{citation|last1=Ashton |first1=P. J. |author-link1= |last2=Scott |first2=W. E. |author-link2= |last3=Sten |first3=D.J. |author-link3= |last4=Wells |first4=R. J. |author-link4= |title=The chemical control programme against the water hyacinth Eichhornia crassipes (Mart.) Solm on Hartbeespoort Dam |journal=South African Journal of Science |volume=75 |date=1979 |url=https://books.google.com/books?id=9uVAAQAAIAAJ&q=crassipes |pages=303–306}}</ref>

<ref name=brown>{{cite magazine|last=Brown |first=James |title=Water hyacinth control in fishing waters |magazine=Louisiana Conservation Review |volume=10 |number=2 |year=1941 |url=https://books.google.com/books?id=JvtRAQAAMAAJ&q=japanese |page=9 |publisher=Department of Conservation, State of Louisiana}} [https://archive.org/details/louisianaconsumm1941depa/page/8 Alt URL]</ref>

<ref name=datta&baneriee>{{cite journal|last1=Datta |first1= S. C. |author-link1= |last2=Banerjee |first2=A. K. |author-link2=|title=Useful Weeds of West Bengal Rice Fields |journal=Economic Botany |volume=32 |number=3 |date=1978 |page=302 |doi= 10.1007/BF02864704 |jstor=4253961|s2cid= 29531285|doi-access=free |bibcode= 1978EcBot..32..297D }}</ref>

<ref name=doughty&turner>{{cite book|last1=Doughty |first1=Robin W. |author-link1= |last2=Turner |first2=Matt Warnock |author-link2= |title=Unnatural Texas?: The Invasive Species Dilemma |publisher=Texas A&M University Press |year=2019 |url=https://books.google.com/books?id=hr6GDwAAQBAJ&pg=PA51 |pages=54–55, 246 nn26–27 |isbn=978-1-623-49705-7}}</ref>

<ref name=douglas>{{cite book|last=Douglas |first=Lake |author-link= |title=Public Spaces, Private Gardens: A History of Designed Landscapes in New Orleans |publisher=LSU Press |year=2011|url=https://books.google.com/books?id=omhLYIRqH-wC&pg=PA54 |pages=54–55, 246 nn26–27 |isbn=978-0-807-13838-0}}</ref>

<ref name=habiba&shaw>{{citation|last1=Habiba |first1=Umma |author-link1= |last2=Shaw |first2=Rajbi |author-link2=|title=6. Bangladesh Experiences of Community-Based Disaster Risk Reduction |editor-last=Shaw |editor-first=Rajib |editor-link= |work=Community Based Disaster Risk Reduction |publisher=Emerald Group Publishing |year=2012 |url=https://books.google.com/books?id=lr_2aTnmUnAC&pg=PA102 |page=102 |isbn=978-0-857-24867-1}}</ref>

<ref name=husain>{{cite magazine|last=Husain |first=Anwar |author-link= |title=Silent Scourges of East Pakistan |journal=Perspective |volume=3 |number=1 |date=July 1969 |url=https://books.google.com/books?id=TkoDAAAAMAAJ&q=%22kachuri%22+%22bengali%22 |page=261}}</ref>

<ref name=kaneko>{{cite book|last=Kaneko |first=Yukiko |author-link= |title=Chotto wa no aru kurashi ga nandaka totemo wakuwaku suru |script-title=ja:ちょこっと和のある暮らしがなんだかとてもワクワクする! |publisher=Subarusha |year=2006|url=https://books.google.com/books?id=2eLfAAAAQBAJ&pg=PT28 |isbn=978-4-883-99555-4}}</ref>

<ref name=kojien>"[https://books.google.com/books?id=8rAPAAAAYAAJ&q=%E3%83%9B%E3%83%86%E3%82%A4%E3%82%A2%E3%82%AA%E3%82%A4 Hotei-aoi ほてい-あおい【布袋葵】]", ''Kojien'', 4th ed., 1991.</ref>

<ref name=mack>{{cite journal|last=Mack |first=Richard N. |author-link=:en:Richard N. Mack |title=The Commercial Seed Trade: An Early Disperser of Weeds in the United States |journal=Economic Botany |volume=45 |number=2 |date=1991 |pages=265–266 |jstor=4255340 |publisher=Springer on behalf of New York Botanical Garden Press|doi=10.1007/BF02862053 |bibcode=1991EcBot..45..257M |s2cid=36826088}}</ref>

<ref name=marsh>{{cite book|last=Douglas |first=Lake |author-link= |title=Loony Louisiana! |publisher=Carole Marsh Louisiana Bks |year=1992 |url=https://books.google.com/books?id=IyLxhXLhFPwC&pg=PT18 |isbn=0-793-37321-2}}</ref>

<ref name="mooallem2013">{{cite magazine |last=Mooallem |first=John |title=American Hippopotamus |magazine=The Atavist |volume=32 |year=2013 |location=New York |url=https://magazine.atavist.com/story/10799 |access-date=2017-11-14 |asin=B00HEWJTF4 |postscript=; |archive-date=April 15, 2021 |archive-url=https://web.archive.org/web/20210415000659/https://magazine.atavist.com/story/10799 }} Mooallem's piece was also featured in {{cite magazine |date=20 December 2013 |last=Miller |first=Greg |title=The Crazy, Ingenious Plan to Bring Hippopotamus Ranching to America |magazine=Wired |url=https://www.wired.com/wiredscience/2013/12/hippopotamus-ranching |issn=1059-1028 }}</ref>

<ref name=stall>{{cite book|last=Stall |first=Gaspar J. "Buddy" |author-link= |title=Buddy Stall's Louisiana Potpourri |publisher=Pelican Publishing |year=1998 |url=https://books.google.com/books?id=-cm80_-6o0gC&pg=PA81 |page=81 |isbn=1-56554-427-7}}</ref>

<ref name=stirton>{{cite book|last=Stirton |first=C. H. |author-link= |title=Plant Invaders: Beautiful, But Dangerous: a Guide to the Identification and Control of Twenty-six Plant Invaders of the Province of the Cape of Good Hope |publisher=Department of Nature and Environmental Conservation of the Cape Provincial Administration |year=1983 |url=https://books.google.com/books?id=XmY_AAAAYAAJ&q=%22waterhiasint%22+1884 |page=68 |isbn=978-0-798-40094-7}}</ref>

<ref name=tricker>{{cite magazine |last=Tricker |first=William |author-link=William Tricker |title=The Water Garden: a quarter century of aquatics |magazine=Gardening |volume=18 |issue=430 |date=1 August 1910 |url=https://books.google.com/books?id=atlKAQAAMAAJ&pg=PA338 |pages=338}}</ref>

<ref name=weeds>{{cite book|last1=Dickinson |first1=Richard |author-link1= |last2=Royer |first2=France |author-link2=|title=Weeds of North America |publisher=University of Chicago Press |year=2014 |url=https://books.google.com/books?id=bU8EDQAAQBAJ&pg=PA625 |page=625 |isbn=978-0-226-07658-4 |quotation=Water hyacinth forms large floating mats.. Under ideal conditions populations may double in size every 6–18 days}}.</ref>

<ref name=west-point>{{cite book|editor-last=Washington Cullum |editor-first=George |editor-link= |editor-last2=Holden |editor-first2=Edward Singleton |editor-link2= |chapter=William H. H. Benyaurd |title=Biographical Register of the Officers and Graduates of the U.S. Military Academy, at West Point, N.Y. |publisher=Houghton, Mifflin |year=1901 |chapter-url=https://books.google.com/books?id=-tI-AQAAMAAJ&pg=PA139 |pages=138–139}}</ref>

<ref name=wise&zimmermann>{{citation |last1=Wise |first1=R.M. |author-link1= |last2=Wilgen |first2=B.W. van |author-link2= |last3=Hill |first3=M.P. |author-link3= |last4=Schulthess |first4=F. |author-link4= |last5=Tweddle |first5=D. |author-link5= |last6=Chabi-Olay |first6=A. |author-link6= |last7=Zimmermann |first7=H.G. |author-link7= |title=The Economic Impact and Appropriate Management of Selected Invasive Alien Species on the African Continent FINAL REPORT |publisher=Global Invasive Species Programme |date=February 2007 |url=http://www.issg.org/pdf/publications/GISP/Resources/CSIRAISmanagement.pdf |page=7 |access-date=January 11, 2020 |archive-date=June 10, 2019 |archive-url=https://web.archive.org/web/20190610170423/http://www.issg.org/pdf/publications/GISP/Resources/CSIRAISmanagement.pdf }}. CSIR Report Number: CSIR/NRE/RBSD/ER/2007/0044/C</ref>

<ref name=wunderlich>{{cite journal|last=Wunderlich |first=William E. |author-link= |title=Machines Combat Aquatic Growth |journal=The Military Engineer |volume=33 |number=1 |year=1940 |url=https://books.google.com/books?id=CAHnAAAAMAAJ&q=%22louisiana%22+1884+%22water+hyacinth%22 |page=517 |publisher=Society of American Military Engineers}}</ref>

<ref name="US-ban-law">{{cite act|url=http://www.govinfo.gov/app/details/USCODE-2011-title18/USCODE-2011-title18-partI-chap3-sec46|title=Transportation of water hyacinths|legislature=United States Congress|date=1 August 1956|type=Bill|index=18 U.S. Code § 46}}</ref>

<ref name="US-ban-law-repealed">{{cite act|url=https://www.congress.gov/bill/116th-congress/house-bill/133|title=TITLE X--CLEAN UP THE CODE ACT OF 2019 SEC. 1002. REPEALS. The following provisions of title 18, United States Code, are repealed: (1) Section 46 relating to transportation of water hyacinths.|date=27 December 2020}}</ref>

}}

=== Bibliography === {{refbegin}} * {{cite journal|last=Barrett |first=Spencer C. H. |author-link=Spencer C. H. Barrett |title=Waterweed Invasions |journal=Scientific American |volume=261 |number=4 |date=October 2004 |pages=90–97 |jstor=24987444|doi=10.1038/scientificamerican1089-90}} * {{cite book|last=Duke |first= J. |title=Handbook of Energy Crops |url=https://hort.purdue.edu/newcrop/duke_energy/dukeindex.html |date=1983 |publisher=Purdue University}} ([https://hort.purdue.edu/newcrop/duke_energy/refa-f.html Complete List of References]) * {{cite book|last1=Gopal |first1=Brij |author-link1= |last2=Sharma |first2=K. P. |author-link2=|title=Water-hyacinth (Eichhornia Crassipes): The Most Troublesome Weed of the World |publisher=Hindasia |date=1981 }} * {{citation|ref={{SfnRef|Ishii|Ninjo|Norinao|Maeda|2001}} |last1=Ishii |first1=Takeshi |author-link1= |last2=Ninjyou |first2=Hiroyuki |author-link2= |last3=Norinao |first3=Hideki |author-link3= |last4=Maeda |first4=Hironobu |author-link4= |last5=Yamashina |first5=Youko |author-link5= |title=世界に分布するホテイアオイとその水質浄化並びに資源としての有効利用の研究(I) |trans-title=A Study on Water Hyacinth all over the World; The Usefulness for Water Purification and Agricultural (or Natural) Resources (I) |journal=Water Science / Suiri Kagaku 水利科学 |volume=45 |number=2 |year=2001|doi=10.20820/suirikagaku.45.2_17 |pages=17–33 |publisher= |language=ja}} * {{cite journal|last=Kadono |first=Yasuro |author-link= |title=Alien aquatic plants naturalized in Japan: history and present status |journal=Global Environmental Research |volume=8 |number=2 |year=2004 |url=http://www.airies.or.jp/attach.php/6a6f75726e616c5f30382d32656e67/save/0/0/08_2-07.pdf |pages=163–169}} * {{cite book|last=Kitunda |first=Jeremiah Mutio |author-link= |title=A History of the Water Hyacinth in Africa: The Flower of Life and Death from 1800 to the Present |publisher=Lexington Books |year=2017 |url=https://books.google.com/books?id=quZCDwAAQBAJ&pg=PR24 |isbn=978-1-498-52463-6}} * {{citation|last=Klorer |first=John |author-link= |title=The Water Hyacinth Problem |journal=Journal of the Association of Engineering Societies |volume=42 |year=1909 |url=https://books.google.com/books?id=fFg2AQAAMAAJ&pg=PA42 |pages=42–48}} * {{cite book|last=Monsod |first=Godofredo G. |author-link= |title=Man and the water hyacinth |publisher=Vantage Press |year=1979 |isbn=978-0-533-03824-4 |url=https://books.google.com/books?id=9HQ0AAAAMAAJ&q=%22Japanese+trouble%22 }} * {{cite journal|last1=Penfound |first1=Wm. T. |author-link1= |last2=Earle |first2=T. T. |author-link2= |title=The Biology of the Water Hyacinth |journal=Ecological Monographs |volume=18 |number=4 |date=October 1948 |pages=447–472 |jstor=1948585|doi=10.2307/1948585|bibcode=1948EcoM...18..447P }} * {{cite journal|last=Vietmeyer |first=Noel D. |author-link= |title=Beautiful Blue Devil |journal=Natural History |volume=84 |number=9 |year=1975 |url=https://books.google.com/books?id=OUAmp5RamkAC&q=%22blue%20devil%22 |pages=65–73}} * {{cite journal|last=Webber |first=H. J. |author-link= |title=The Water Hyacinth, and its Relation to Navigation in Florida |journal=U. S. Dept. Agr. Div. Bot. Bulletin |number=18 |year=1897 |url=https://archive.org/details/waterhyacinthits00webb/page/10 |pages=1–20}} * {{cite journal|last1=Wolverton |first1=Billy C. |author-link1=Bill Wolverton |last2=McDonald |first2=Rebecca C. |author-link2= |title=The Water Hyacinth: From Prolific Pest to Potential Provider |journal=Ambio |volume=8 |number=1 |year=1979 |pages=2–9|jstor=4312402 |publisher=Springer on behalf of Royal Swedish Academy of Sciences}} {{refend}}

==External links== {{Commons}} {{Wikispecies}} * [http://www.hear.org/pier/species/eichhornia_crassipes.htm ''Eichhornia crassipes''] {{WestAfricanPlants|Eichhornia crassipes}} * [https://www.invasivespeciesinfo.gov/profile/water-hyacinth Species Profile – Water Hyacinth (''Eichhornia crassipes'')], National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Water Hyacinth. * [http://www.flowersinisrael.com/Eichhorniacrassipes_page.htm Eichhornia crassipes] {{Webarchive|url=https://web.archive.org/web/20151119064748/http://www.flowersinisrael.com/Eichhorniacrassipes_page.htm |date=November 19, 2015 }} Israel Wildflowers and native plants * [http://practicalaction.org/water-hyacinth Practical uses of Water Hyacinth] * [https://web.archive.org/web/20160304054947/http://cmsdata.iucn.org/downloads/hyacinth_leaflet.pdf IUCN Leaflet on ''E. crassipes'' in the context of Lake Tanganyika] * [https://aquaplant.tamu.edu/plant-identification/alphabetical-index/water-hyacinth/ "Water hyacinth"], AquaPlant Profile

Category:Pontederiaceae Category:Aquatic plants Category:Flora of the Amazon