Gnetum africanum

Gnetum africanum (eru or African Jointfir) is a vine gymnosperm species found natively throughout tropical Africa. Though bearing leaves, the genus Gnetum are gymnosperms, related to pine and other conifers. Gnetum africanum has numerous common names and is grown in various countries across Africa, including: Cameroon (Eru, okok, m’fumbua, or fumbua), Angola (KoKo), Nigeria (ukase or afang), Gabon (KoKo), Central African Republic (KoKo), Congo (KoKo), and the Democratic Republic of Congo (m’fumbua or fumbua). Gnetum africanum has also been referred to as a form of ‘wild spinach’ in English. Gnetum africanum is traditionally a wild vine and is considered to be a wild vegetable. It is a perennial that grows approximately 10 metres long, with thick papery-like leaves growing in groups of three. The leaves may grow approximately 8 cm long, and at maturity the vine will produce small cone-like reproductive structures. The seeds of the vine resemble a fleshy fruit, sized 10–15 mm × 4–8 mm, and are red-orange in colour when fully ripe. Gnetum africanum may also be known as G. africanum or G. buchholzianum, and are the only two vine species from the gnetum family. There are currently no gene banks for Gnetum africanum, but approximately 19 varieties of the species have been planted in Cameroon’s Limbe Botanic Garden to begin a gene bank. Gnetum africanum is found mainly in the humid tropical forest regions of Central African Republic, Cameroon, Gabon, Democratic Republic of the Congo and Angola. It has been found in primary and secondary semi-deciduous humid forests, both in dense and sunny transitional savannah locations, ranging from sea-level to 1200 meter altitude. The shade tolerant vine does not grow well in direct sunlight and can be found climbing on middle and under-story trees. This vine will grow in all seasons and typically spreads along forest floors. The vine grows in two ways: through rhizomes, or through new shoots that grow where the stem has been cut. As Gnetum africanum is a wild forest vine, it tends to grow best in shaded areas. Input requirements for Gnetum africanum have not yet been established, and nutrient requirements are currently unknown as well. This is likely due to the fact that the vine is traditionally a wild vegetable opposed to a cultivated crop, and so its domestication potential has remained unrealized. However, it has been noted that the vine grows best in well-shaded areas similar to that of a forest, as too much sunlight can burn the vine and produce substandard leaves for selling purposes. It has also been noted that the vine does not grow particularly well in very moist conditions such as marshes and swamps. Gnetum africanum has been found to be negatively impacted if grown on or next to termite infected wood or trees. However, the productivity of the vine appears to be resistant to a significant proportion of diseases. The vine is largely understudied and more research is needed to verify plant susceptibility and resilience to viruses, diseases, and fungi. Gnetum africanum depletion is largely associated with tree felling and overexploitative forestry practices. Overexploitation is partly caused by unsustainable forest clearing practices throughout regions in Africa. Since Gnetum africanum grows best in shaded areas it could be used as a complimentary crop on tree farms. Specifically, it has been suggested that the vine could be used as a complimentary crop for rubber and oil trees. However, the necessity for shaded, but not excessively moist, conditions may make it difficult for poor farmers to grow Gnetum africanum if they lack access to suitable lands. However, since Gnetum africanum grows via rhizomes it is not labour-intensive, therefore allowing farmers to focus physical capital elsewhere.