Dioscorea bulbifera, the Air potato, is a yam

Yam (vegetable)

Yam is the common name for some species in the genus Dioscorea . These are perennial herbaceous vines cultivated for the consumption of their starchy tubers in Africa, Asia, Latin America and Oceania...

 species. It is also known as Varahi in Sanskrit

Sanskrit

Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...

, Kaachil in Malayalam and Dukkar Kand in Marathi

Marathi language

Marathi is an Indo-Aryan language spoken by the Marathi people of western and central India. It is the official language of the state of Maharashtra. There are over 68 million fluent speakers worldwide. Marathi has the fourth largest number of native speakers in India and is the fifteenth most...

. The Air potato plant is native to Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 and Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

.

Description

Dioscorea bulbifera is a perennial

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 vine

Vine

A vine in the narrowest sense is the grapevine , but more generally it can refer to any plant with a growth habit of trailing or scandent, that is to say climbing, stems or runners...

 with broad leaves and two types of storage organ

Storage organ

A storage organ is a part of a plant specifically modified for storage of energy or water. Storage organs often grow underground, where they are better protected from attack by herbivores. Plants that have an underground storage organ are called geophytes in the Raunkiær plant life-form...

s. The plant forms bulb

Bulb

A bulb is a short stem with fleshy leaves or leaf bases. The leaves often function as food storage organs during dormancy.A bulb's leaf bases, known as scales, generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions. At the center of the bulb is...

ils in the leaf axils of the twining stems, and tuber

Tuber

Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...

s beneath the ground. These tubers are like small, oblong potato

Potato

The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...

es, and they are edible and cultivated as a food crop

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

, especially in West Africa

West Africa

West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...

. The tubers 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

Sweet potato

The sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...

es. The air potato is one of the most widely-consumed yam species.It can grow up to 150 feet tall.
Air potato can grow extremely quickly, roughly 8 inches per day, and eventually reach over 60 feet long. It typically climbs to the tops of tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s and has a tendency to take over native plant

Native plant

Native plant is a term to describe plants endemic or naturalized to a given area in geologic time.This includes plants that have developed, occur naturally, or existed for many years in an area...

s. New plants develop from bulbils that form on the plant, and these bulbils serve as a means of dispersal

Biological dispersal

Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...

. The aerial stems

Plant stem

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

 of air potato die back in winter

Winter

Winter is the coldest season of the year in temperate climates, between autumn and spring. At the winter solstice, the days are shortest and the nights are longest, with days lengthening as the season progresses after the solstice.-Meteorology:...

, but resprouting

Sprouting

Sprouting is the practice of germinating seeds to be eaten either raw or cooked.They are a convenient way to have fresh vegetables for salads, or otherwise, in any season and can be germinated at home or produced industrially...

 occurs from bulbils and underground tubers. The primary means of spread and reproduction

Plant reproduction

Plant reproduction is the production of new individuals or offspring in plants, which can be accomplished by sexual or asexual means. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from the parent or parents...

 are via 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 Florida.

Uses

Air potato has been used as a folk remedy

Home remedy

A home remedy is a treatment to cure a disease or ailment that employs certain spices, vegetables, or other common items. Home remedies may or may not have medicinal properties that treat or cure the disease or ailment in question, as they are typically passed along by laypersons...

 to treat conjunctivitis

Conjunctivitis

Conjunctivitis refers to inflammation of the conjunctiva...

, diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

 and dysentery

Dysentery

Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...

, among other ailments.

Toxicity

Uncultivated forms, such as those found growing wild in Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 can be poison

Poison

In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....

ous. These varieties contain the steroid

Steroid

A steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...

, diosgenin

Diosgenin

Diosgenin, a steroid sapogenin, is the product of hydrolysis by acids, strong bases, or enzymes of saponins, extracted from the tubers of Dioscorea wild yam, such as the Kokoro...

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

Synthetic

Synthesis, the combination of two or more parts, whether by design or by natural processes. Furthermore, it may imply being prepared or made artificially, in contrast to naturally.-In the sense of combination:* Synthetic position, a concept in finance...

 steroidal hormone

Hormone

A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

s, such as those used in hormonal contraception

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 hormonal method—the combined oral contraceptive...

. There have been claims that even the wild forms are rendered edible after drying and boiling

Boiling

Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environmental pressure. While below the boiling point a liquid...

, leading to confusion over actual toxicity

Toxicity

Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...

.

Invasive species

In some places, such as Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 where it is considered a noxious weed, it is an invasive species

Invasive species

"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

 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

Shoots are new plant growth, they can include stems, flowering stems with flower buds, and leaves. The new growth from seed germination that grows upward is a shoot where leaves will develop...

s later.

External Links

• Species Profile- Air Potato (Dioscorea bulbifera), National Invasive Species Information Center, United States National Agricultural Library
  United States National Agricultural Library
  The United States National Agricultural Library 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...
  
  . Lists general information and resources for air potato.

Further reading

• Van Wyk, Ben-Erik (2005). Food Plants of the World. Portland, Oregon: Timber Press, Inc. ISBN 0-88192-743-0
• http://plants.ifas.ufl.edu/node/133 General information about Dioscorea Bulbifera from University of Florida