Aerial Yam, Air Potato
Dioscorea bulbifera
Family: Dioscoreaceae
What it is like
Dioscorea bulbifera or commonly known as Aerial Yam is a perennial, non-spiny, climbing plant up to 10 m long. It has a woody, tuberous rootstock and heart-shaped broad leaves. The twining stems produce aerial axillary bulbils that are edible. The plant is native to Africa, southern Asia, Maldives, and northern Australia. Some varieties are edible and cultivated as a food crop while others are poisonous. Aerial tubers should be thoroughly to destroy toxic alkaloid. Tubers are also cooked. It is also used medicinally to treat conjunctivitis, diarrhoea, dysentery. Root juice is taken to expel threadworm. Fruits are used to treat boils and fevers.
Dioscorea bulbifera is an evergreen Perennial Climber growing to 10 m (32ft) by 0.5 m (1ft 8in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 9. The flowers are pollinated by Wind, Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid and very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil and can tolerate drought.
Height (m): 10
Where it is found
Not known
E. Asia - Malaysia.
Conservation Status: This taxon has not yet been assessed.
Countries/locations it is found in
Africa, Asia, Australia, Bangladesh, Benin, Bhutan, Brazil, Burkina Faso, Burma, Cambodia, Cameroon, Central Africa, Central America, China, Colombia, Comoros, Congo DR, Congo R, Cook Is., Costa Rica, Côte d'Ivoire, East Africa, East Timor, Ethiopia, Fiji, Gambia, Ghana, Guiana, Guinea, Guinée, GuineaBissau, Haiti, Himalayas, India, Indochina, Indonesia, Ivory Coast, Jamaica, Japan, Kenya, Korea, Laos, Liberia, Madagascar, Malawi, Malaysia, Mali, Mauritius, Myanmar, Namibia, Nepal, New Caledonia, Niger, Nigeria, North America, Northeastern India, Pacific, Pakistan, Papua New Guinea, Philippines, Reunion, Samoa, SE Asia, Senegal, Sierra Leone, Sikkim, Solomon Islands, Southern Africa, South America, Sri Lanka, St Lucia, Suriname, Tahiti, Taiwan, Thailand, Timor-Leste, Togo, Tonga, Tanzania, Uganda, USA, Vanuatu, Venezuela, Vietnam, West Africa, West Indies, Yap, Zambia
How it is used
Food
Rating: 4
Aerial tubers - cooked. An agreeable taste, they can be boiled, baked, fried etc. They must be thoroughly cooked in order to destroy toxic alkaloids. Wild forms of the plant are always toxic raw, though selected cultivars have been developed that are much lower, or even free from, the toxins. The tubers are produced, and can be harvested, over a long period of time. Root - cooked. Roots are usually around 0.5kg, though they can be up to 1.5kg. They are not always produced by the plants. The inflorescences are apparently eaten.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 2
The juice of the roots is taken to expel threadworm. The juice is dripped into wounds to expel worms and germs. Both the tuber and the bulbil of wild races have medicinal uses. In particular they are used externally, usually as a poultice, to treat wounds, sores, boils and inflammations; in dressings for treating dermal parasitic and fungal infections; or crushed, mixed with palm oil, and massaged onto areas of rheumatism, and for troubles of the breasts and for jiggers. In India the tuber is considered to be diuretic and to be a remedy for diarrhoea and haemorrhoids. The fruits are used to treat boils and for fever. Sap expressed from the vine stems is applied to treat purulent ophthalmia, and for snake-bite. The leaves are used, often by steam-distillation, against pink-eye. Various medically active substances have been detected in the plant. Dioscorine has been detected in the tuber, though certain Nigerian material has been reported free of the alkaloid. Alkaloids have been reported from the leaves and stems and particularly in the fruits. Diosgenin has been detected at 0?45% concentration. Saponin is present and a number of other pharmacologically active substances.
Antidiarrhoeal: Provides symptomatic relief for diarrhoea. Also see Astringent.
Antifungal: An agent that inhibits or destroys fungi. Used in the treatment of various fungal problems such as candida.
Antihaemorrhoidal: Treats haemorrhoids (piles). This would probably be best added to another heading.
Antiinflammatory: Reduces inflammation of joints, injuries etc.
Antirheumatic: Treats rheumatism.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Febrifuge: Reduces fevers.
Ophthalmic: Treats eye complaints.
Parasiticide: Treats external parasites such as ringworm This should perhaps be joined with Parasiticide in
Poultice: A moist, usually warm or hot, mass of plant material applied to the skin in the treatment of burns etc.
Skin: Plants used in miscellaneous treatments for the skin.
Other
Rating: 0
Other Uses: None known
Parasiticide: Kills external body parasites such as hair lice.
Industrial Crop: Starch: Materials and chemicals include bioplastics, paper, cardboard, solvents, paints, glues etc. Plants are usually pods, starchy fruits, nuts & seeds, starchy trunks.
Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.
Staple Crop: Basic Starch: The Carbon Farming Solution. Eric Toensmeier.
Industrial Crop: Starch: Materials and chemicals include bioplastics, paper, cardboard, solvents, paints, glues etc. Plants are usually pods, starchy fruits, nuts & seeds, starchy trunks.
Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.
Staple Crop: Basic Starch: The Carbon Farming Solution. Eric Toensmeier.
Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
A plant of the moist, lowland tropics. It grows best in areas where annual daytime temperatures are within the range 20 - 30°c, but can tolerate 12 - 38°c. It can be killed by temperatures of 9°c or lower. It prefers a mean annual rainfall in the range 1,200 - 2,600mm, but tolerates 900 - 4,000mm. It prefers a well-defined dry season of 2 - 3 months. This species is more tolerant than most other yams of temperatures below 25°c. For best yields, this species requires a deep, well-drained, sandy loam that is not liable to water-logging. Prefers a pH in the range 6 - 6.7, tolerating 5.3 - 8. Daylengths of more than 12 hours are preferred during the early growing season since this encourages vegetative growth; daylengths of less than 12 hours towards the end of the growing season will encourage tuber formation and development. The bulbils are produced in 5 - 6 months from planting, though some forms can produce a crop in as little as 3 months. Average yields of the bulbs are in the range of 3 - 5 tonnes per hectare, though up to 15 tonnes have been obtained. The bulbils of selected cultivars tend to be angular with a flattened shape and a skin-colour which evokes the name 'turkey liver yam'. They may attain as much as 2 kg in weight but an average weight is about 0.5 kg. Races with increased bulbil production tend to show a reduction of the tuber, and in those with the highest bulbil return the tuber is but a woody rootstock. Bulbils are ready for harvesting when they fall off the plant at a slight touch. When produced, yields of 2 - 8 tonnes per hectare of the roots have been obtained. There are some named varieties. Aerial yam is a species of many races. The wild ones, which are toxic raw, have globose, dark brown to liver-coloured, non-angular bulbils which serve as a famine-food, as do the tubers. Wild strains are often planted intermixed with or on the perimeter of plantings of improved races as a protection against thieving. Cattle eating them accidentally may be fatally poisoned showing frothing at the mouth and bloating. The species is in the process of ennoblement and selected cultivars show in varying degree bitterness and poisonousness. Of some races even after prolonged preparation the bulbils remain bitter. Superior races are said to be very palatable and sweet, and to be entirely free from toxic substances so that consumption, even raw, is safe. The skin is grey, lighter coloured than the wild forms, and the flesh is pale yellow to near white. A dioecious species, both male and female plants need to be grown if seed is required. Flowering time: Late Fall/Early Winter. Bloom color: Pale Green Green
Propagating it: Seed - rarely produced, they are not normally used to propagate this species. Cuttings of tubers. Small tubers can be cut into 2 - 4 sections, larger ones into 6 - 8 sections. Each section should have 2 - 3 dormant buds. The cut tuber is often left in the sun for several hours to promote wound healing and reduce the risk of fungal infection. Aerial tubers can also be used, they usually produce vigorous plants. The aerial bulbs are often divided into 2 or more equal sized pieces. Plants often need to be grown for two seasons in order to produce full-size aerial bulbs.
Best place to grow:
Habit: Perennial Climber
Hardiness: 9-12
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves. The aerial bulbs of this species contain toxic substances, including the alkaloid dioscorine. This can be destroyed by thorough cooking. Asiatic forms of the plant usually contain less alkaloids than plants originating in Africa. There are forms that are almost or entirely free of toxins.(Parts of plant are poisonous if ingested)
Described as one of the most aggressive weeds ever introduced into the United States (Florida Exotic Pest Plant Council, 2008). It is a highly invasive plant included in the Global Compendium of Weeds (Randall, 2012), and which creates management problems in many parts of the world. Currently, this species is classified as a “noxious weed” in Alabama and Florida and as an invasive species in Cuba, the Bahamas, Puerto Rico and Pacific Islands including Hawaii, Fiji, French Polynesia, Niue and Palau.
Its other names
Local names
Abubu, Acom, Aerial Yam, Agbanio, Akam, Apuereka, Ban tarul, Banalu, Bantarul, Basel phauk, Batata de rama, Bayag-toro, Belloi, Bubaia, Cambare marron, Cara de are, Catoco, Chedupaddu-dumpa, Cheeky yam, Chitangula, Cu,aerial yam air potato air-potato ban tarul bengo nari bhyakur bitter yam brotwurzel buk bulb-bearing yam cheeky yam diha dukarkanda dukkarkanda genthi ghar tyaur githa heggenusu hisaki hoei-oepas hoi huang yao zi huángyàozi igname bulbifère inhame kamfo kanthamul kaya pendazam khashyo khe kisi kukur tarul kunta genusu ofika oviala papa voladora pas phor potatisjams potato yam pousse en l'air ratalu sakkisak tarul teme varahi varahi kand varahi kanda varahi (rhizome) varahika?da yamswurzel ñame de gunda
Synonyms
Dioscorea crispata Roxb. Dioscorea heterophylla Roxb. Dioscorea latifolia Benth. Dioscorea oppositif