''Dioscorea bulbifera'' (commonly known as the air potato, air yam, bitter yam, cheeky yam, potato yam, aerial yam, and parsnip yam) is a species of true yam in the yam

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

, Dioscoreaceae. It is native to Africa, Asia and northern Australia. It is widely cultivated and has become naturalized in many regions (Latin America, the West Indies, the southeastern United States, and various oceanic islands). It is also known as the up-yam in Nigerian Pidgin English, since the plant is cultivated more for its

bulbil A bulbil (also referred to as a bulbel, bulblet, and/or pup) is a small, young plant that is reproduced vegetatively from axillary buds on the parent plant's stem or in place of a flower on an inflorescence. These young plants are clones of the p ...

s than for its

tuber Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reproduc ...

Description

''Dioscorea bulbifera'' is a

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

vine with broad, alternate leaves, and two types of

storage organ A storage organ is a part of a plant specifically modified for storage of energy (generally in the form of carbohydrates) or water. Storage organs often grow underground, where they are better protected from attack by herbivores. Plants that have ...

s. The plant forms

bulbils A bulbil (also referred to as a bulbel, bulblet, and/or pup) is a small, young plant that is reproduced vegetatively from axillary buds on the parent plant's stem or in place of a flower on an inflorescence. These young plants are clones of the ...

in the leaf axils of the twining stems, and tubers beneath the ground. These tubers are like small, oblong potatoes. Some varieties are edible and cultivated as a food crop, especially in

West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

. The tubers of edible varieties often have a bitter taste, which can be removed by boiling. They can then be prepared in the same way as other yams, potatoes, and

sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledonous plant in the morning glory family, Convolvulaceae. Its sizeable, starchy, sweet-tasting tuberous roots are used as a root vegetable, which is a staple food in parts of ...

es. Air potato can grow extremely quickly, roughly 8 inches per day, and eventually reach over 60 ft long. It typically climbs to the tops of trees and has a tendency to take over

native plant In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...

s. New plants develop from bulbils that form on the plant, and these bulbils serve as a means of dispersal. The aerial stems of air potato die back in winter, but resprouting occurs from bulbils and underground tubers. The primary means of spread and

reproduction Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: Asexual reproduction, asexual and Sexual ...

are by the bulbils. The smallest bulbils make control of air potato difficult due to their ability to sprout at a very small stage. The vine produces small white flowers; however, these are rarely seen when it grows in places such as Florida. The fruits are capsules.

Uses

Air potato has been used as a folk remedy to treat

conjunctivitis Conjunctivitis, also known as pink eye or Madras eye, is inflammation of the conjunctiva, the thin, clear layer that covers the white surface of the eye and the inner eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness ...

diarrhoea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

, and

dysentery Dysentery ( , ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications may include dehyd ...

, among other ailments. ''D. bulbifera'' is highly important to the

Tiwi people The Tiwi people (or Tunuvivi) are one of the many Aboriginal Australian, Aboriginal groups of Australia. Nearly 2,000 Tiwi people live on Bathurst Island (Northern Territory), Bathurst and Melville Island, Northern Territory, Melville Islands, ...

of Australia, who use it in an important ceremony called ''kulama''. During the ceremony, the tubers are ritually cooked, and eaten on the third day.

Toxicity

Uncultivated forms, such as those found growing wild in Florida, can be poisonous. These varieties contain the

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

diosgenin Diosgenin, a phytosteroid sapogenin, is the product of hydrolysis by acids, strong bases, or enzymes of saponins, extracted from the tubers of '' Dioscorea'' wild yam species, such as the Kokoro. It is also present in smaller amounts in a num ...

, which is a principal material used in the manufacture of a number of

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

steroidal

hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

s, such as those used in

hormonal contraception Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original ...

. There have been claims that even the wild forms are rendered edible after drying and boiling, leading to confusion over actual

toxicity Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacteria, bacterium, or plant, as well as the effect o ...

Invasive species

In some places, such as Florida, it is considered a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

because of its quick-growing, large-leafed vine that spreads tenaciously and shades out any plants growing beneath it. The bulbils on the vines sprout and become new vines, twisting around each other to form a thick mat. If the plant is cut to the ground, the tubers can survive for extended periods and send up new

shoot Shoot most commonly refers to: * Shoot (botany), an immature plant or portion of a plant * Shooting, the firing of projectile weapons * Photo shoot, a photography session; an event wherein a photographer takes photographs Shoot may also refer t ...

s later. The

leaf beetle The beetle family Chrysomelidae, commonly known as leaf beetles, includes over 37,000 (and probably at least 50,000) species in more than 2,500 genera, making it one of the largest and most commonly encountered of all beetle families. Numerous s ...

'' Lilioceris cheni'' has been studied and employed as an agent of

biological pest control Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or ot ...

for the plant, with releases in 2012.Field release of ''Lilioceris cheni'' Gressit & Kimoto (Coleoptera: Chrysomelidae) for biological control of air potato, ''Dioscorea bulbifera'' (Dioscoreaceae), in the continental United States: Environmental Assessment.
USDA. 2011.Morgan, C

''Miami Herald'' September 21, 2012.

References

External links

Species Profile - Air Potato (''Dioscorea bulbifera'')
National Invasive Species Information Center,

United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Locate ...

. Lists general information and resources for Air Potato. {{DEFAULTSORT:Dioscorea bulbifera bulbifera Flora of Africa Flora of tropical Asia Flora of China Flora of Eastern Asia Flora of Australia Perennial vegetables Plants described in 1753 Taxa named by Carl Linnaeus Yams (vegetable) Austronesian agriculture