Gnetumis a genus ofgymnosperms,the sole genus in the familyGnetaceaewithin theGnetophyta.They aretropicalevergreentrees,shrubsandlianas.Unlike other gymnosperms, they possessvessel elementsin thexylem.Some species have been proposed to have been the first plants to be insect-pollinatedas their fossils occur in association with extinct pollinatingscorpionflies.[2]Molecular phylogenies based on nuclear and plastid sequences from most of the species indicate hybridization among some of the Southeast Asian species. Fossil-calibrated molecular-clocks suggest that theGnetumlineages now found inAfrica,South AmericaandSoutheast Asiaare the result of ancient long-distance dispersal across seawater.[3][4]
| Gnetum | |
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| Gnetum luofuensein China | |
Scientific classification
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Gnetophyta |
| Order: | Gnetales Mart |
| Family: | Gnetaceae Blume |
| Genus: | Gnetum L. |
| Type species | |
| Gnetum gnemon | |
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| Distribution | |
| Synonyms[1] | |
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Their leaves are rich in phytochemicals such asflavonoidsandstilbenes.Of the species studied so far,Gnetumhave photosynthetic and transpiration capacities which are considerably lower than those of other seed plants, due to the absence of multiple chloroplast genes essential forphotosynthesis,a trait they seem to share with the other living members of Gnetophyta,EphedraandWelwitschia,as well asconifers.[5]There are over 50 different species ofGnetum.[citation needed]
Species
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There are around 50 different species ofGnetum.TheCatalogue of Lifelists 44 species.[9]
- Gnetum interruptumBiye
- Gnetum latispicumBiye
- Gnetumsect.Gnetum
- Gnetumsubsect.Gnetum– 2 species of trees;Southeast Asia,Pacific Islands
- Gnetumsubsect.Micrognemones– 2 species of lianas; tropical westAfrica
- Gnetum africanum– central Africa fromCameroontoAngola
- Gnetum buchholzianum– central Africa fromNigeriatoZaire
- Gnetumsubsect.Araeognemones– 9 species of lianas; tropicalSouth AmericaandCentral America- Ituá
- Gnetum camporum–Venezuela
- Gnetum leyboldii–Costa Rica,Panama,Venezuela,Colombia,Ecuador,Peru,AmazonianBrazil
- Gnetum nodiflorum– Guianas, Venezuela, Colombia, Ecuador, Peru, northwestern Brazil
- Gnetum paniculatum– Guianas, Venezuela, northwestern Brazil
- Gnetum schwackeanum– Amazonas State of southern Venezuela, northwestern Brazil
- Gnetum urens– Guianas, Venezuela, Peru, northwestern Brazil
- Gnetum venosum– Bolívar State of southern Venezuela, northwestern Brazil
- Gnetumsect.Scandentia[Gnetumsect.Cylindrostachys] - about 20 species of lianas; southern Asia
- Gnetumsubsect.Stipitati
- Gnetum arboreum– Luzon in Philippines
- Gnetum contractum– southernIndia
- Gnetum edule– southern India
- Gnetum gracilipes–Yunnan+GuangxiinChina
- Gnetum latifolium– Assam, much of Southeast Asia,New Guinea,Bismarck Archipelago
- Gnetum montanum–Himalayas,southern China, northernIndochina
- Gnetum oblongum–Bangladesh,Myanmar
- Gnetum pendulum– Tibet, southern China
- Gnetum tenuifolium– Peninsular Malaysia,Thailand,Sumatra
- Gnetum ula
- Gnetumsubsect.Sessiles
- Gnetum acutum–Sarawak
- Gnetum bosavicum– Papua New Guinea
- Gnetum catasphaericum– southern China
- Gnetum chinenseYang, Liu, & Chang– northern China
- Gnetum cleistostachyum– southern China
- Gnetum cuspidatum– Indochina,Indonesia,Malaysia, Philippines
- Gnetum diminutum–Borneo
- Gnetum formosum–Vietnam
- Gnetum giganteum– Guangxi in China
- Gnetum globosum–Pahangin Malaysia
- Gnetum gnemonoides– New Guinea, Bismarck Archipelago, Indonesia, Philippines
- Gnetum hainanense– southern China
- Gnetum klossii– Sabah
- Gnetum leptostachyum–Laos,Thailand, Vietnam, Borneo
- Gnetum loerzingii–Sumatra
- Gnetum luofuense–Fujian,Guangdong,Jiangxi
- Gnetum macrostachyum– Indochina, Indonesia, Malaysia, New Guinea
- Gnetum microcarpum– Myanmar, Thailand, Malaysia, Borneo, Sumatra
- Gnetum neglectum– Borneo
- Gnetum oxycarpum– Sumatra
- Gnetum parvifolium– Laos, Vietnam, southern China
- Gnetum raya– Borneo
- Gnetum ridleyi– Peninsular Malaysia
- Gnetumsubsect.Stipitati
Uses
editManyGnetumspecies are edible, with theseedsbeing roasted, and the foliage used as aleaf vegetable.[10]The plant is harvested and yields a useful fiber.[clarification needed]There is no sense of danger in consuming the fruit or the seeds.[11]
There is also a study done on the plant to see if it has any medicinal properties, finding some anti-coagulation effects due to its stilbenoid content. The family Gnetaceae is well known as a rich source of plant-derivedstilbenoidsas well asCyperaceae,Dipterocarpaceae,Fabaceae,andVitaceae.[12]
Conservation
editSome species ofGnetumare in danger of dying out. The habitats are being removed with the trees being cut down to create industry. The tropical rainforest are being destroyed so many of the species are going extinct such asGnetum oxycarpum.The rainforests are being torn down and being turned into farmland.Gnetumlive in only a small part of the rainforest.
Gallery
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Gnetum gnemoncarpellate/female cones -
Gnetum latifoliumstaminate/male cones -
Gathered leaves ofGnetum africanum -
Gnetum gnemonseeds
References
edit- ^Kew World Checklist of Selected Plant Families
- ^Ren, Dong; Labandeira, Conrad C.; Santiago-Blay, Jorge A.; Rasnitsyn, Alexandr; Shih, Chungkun; Bashkuev, Alexei; Logan, M. Amelia V.; Hotton, Carol L.; Dilcher, David (2009)."A Probable Pollination Mode Before Angiosperms: Eurasian, Long-Proboscid Scorpionflies".Science.326(5954):840–847.Bibcode:2009Sci...326..840R.doi:10.1126/science.1178338.PMC2944650.PMID19892981.
- ^Won, Hyosig; Renner, Susanne S. (2005). "The internal transcribed spacer of nuclear ribosomal DNA in the gymnosperm Gnetum".Molecular Phylogenetics and Evolution.36(3):581–597.Bibcode:2005MolPE..36..581W.doi:10.1016/j.ympev.2005.03.011.PMID16099382.
- ^Won, Hyosig; Renner, Susanne S. (2006). "Dating Dispersal and Radiation in the Gymnosperm Gnetum (Gnetales)—Clock Calibration when Outgroup Relationships Are Uncertain".Systematic Biology.55(4):610–622.doi:10.1080/10635150600812619.PMID16969937.
- ^Deng, N.; Hou, C.; Liu, C.; Li, M.; Bartish, I.; Tian, Y.; Chen, W.; Du, C.; Jiang, Z.; Shi, S. (2019)."Significance of Photosynthetic Characters in the Evolution of Asian Gnetum (Gnetales)".Frontiers in Plant Science.10:39.doi:10.3389/fpls.2019.00039.PMC6370715.PMID30804953.
- ^Hou, Chen; Humphreys, Aelys M.; Thureborn, Olle; Rydin, Catarina (April 2015)."New insights into the evolutionary history of Gnetum (Gnetales)".Taxon.64(2):239–253.doi:10.12705/642.12.
- ^Stull, Gregory W.; Qu, Xiao-Jian; Parins-Fukuchi, Caroline; Yang, Ying-Ying; Yang, Jun-Bo; Yang, Zhi-Yun; Hu, Yi; Ma, Hong; Soltis, Pamela S.; Soltis, Douglas E.; Li, De-Zhu; Smith, Stephen A.; Yi, Ting-Shuang; et al. (2021)."Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms".Nature Plants.7(8):1015–1025.bioRxiv10.1101/2021.03.13.435279.doi:10.1038/s41477-021-00964-4.PMID34282286.S2CID232282918.
- ^Stull, Gregory W.; et al. (2021)."main.dated.supermatrix.tree.T9.tre".Figshare.doi:10.6084/m9.figshare.14547354.v1.
- ^ "Gnetum L."Catalogue of Life.RetrievedOctober 24,2024.
- ^Hoe, V.B. and Siong, K.H., "The Nutritional Value of Indigenous Fruits and Vegetables in Sarawak," Asia-Pacific Journal of Clinical Nutrition, Vol. 8, no. 1, 1998, pp 24-31
- ^"Gnetum gnemon | plant | Britannica".Encyclopædia Britannica.RetrievedMay 2,2022.
- ^Kloypan, Chiraphat; Jeenapongsa, Rattima; Sri-In, Piyawit; Chanta, Surin; Dokpuang, Dech; Tip-Pyang, Santi; Surapinit, Nattanan (2012)."Stilbenoids from Gnetum macrostachyum Attenuate Human Platelet Aggregation and Adhesion".Phytotherapy Research.26(10):1564–1568.doi:10.1002/ptr.4605.PMID22511550.S2CID43249684.
External links
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- Gymnosperm Database -Gnetum
- SortingGnetumnames
- Uses ofGnetumin Africa (FAO)ArchivedJanuary 11, 2019, at theWayback Machine
- Kloypan, Chiraphat & Jeenapongsa, Rattima & Sri-In, Piyawit & Chanta, Surin & Dokpuang, Dech & Tip-Pyang, Santi & Surapinit, Serm. (2012). Stilbenoids from Gnetum macrostachyum Attenuate Human Platelet Aggregation and Adhesion. Phytotherapy research: PTR. 26. 1564–8. 10.1002/ptr.4605.
- https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.1002/j.1537-2197.1916.tb05408.xArchivedDecember 22, 2021, at theWayback Machine
- http://www.theplantlist.org/tpl1.1/record/kew-334161...