Gnetum is a genus ofgymnosperms, the sole genus in the familyGnetaceae within theGnetophyta. They aretropicalevergreentrees,shrubs andlianas. Unlike other gymnosperms, they possessvessel elements in thexylem. Some species have been proposed to have been the first plants to be insect-pollinated as 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 theGnetum lineages now found inAfrica,South America andSoutheast Asia are the result of ancient long-distance dispersal across seawater.[3][4]
Their leaves are rich in phytochemicals such asflavonoids andstilbenes. Of the species studied so far,Gnetum have 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,Ephedra andWelwitschia, as well asconifers.[5] There are over 50 different species ofGnetum.[citation needed]
ManyGnetum species are edible, with theseeds being 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-derivedstilbenoids as well asCyperaceae,Dipterocarpaceae,Fabaceae, andVitaceae.[12]
Some species ofGnetum are 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.Gnetum live in only a small part of the rainforest.
^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.
^"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
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