''Calotropis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s in the family

Apocynaceae Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of the ...

, first described as a genus in 1810. It is native to southern Asia and North Africa. They are commonly known as milkweeds because of the

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

they produce. ''Calotropis'' species are considered common

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

s in some parts of the world. The flowers are fragrant and are often used in making floral tassels in some mainland

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...

n cultures. Fibers of these plants are called madar or mader. ''Calotropis'' species are usually found in abandoned farmland.

Botanical description

''Calotropis gigantea'' and ''C. procera'' are the two most common species in the genus. ''Calotropis gigantea'' grows to a height of while ''C. procera'' grows to about . The leaves are sessile and sub-sessile, opposite, ovate, cordate at the base. The flowers are about in size, with umbellate lateral cymes and are colored white to pink and are fragrant in case of ''C. procera'' while the flowers of ''C. gigantea'' are without any fragrance and are white to purple colored, but in rarer cases are also light green-yellow or white. The seeds are compressed, broadly ovoid, with a tufted micropylar coma of long silky hair.

Pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...

is performed by bees (

entomophily Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, some ...

) by the following mechanism: The stigmas and androecia are fused to form a gynostegium. The

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

are enclosed in

pollinia A pollinium (plural pollinia) is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination, as a single unit. This is regularly seen in plants such as orchids and many species of mil ...

(a coherent mass of pollen grains). The

are attached to an adhesive glandular disc at the stigmatic angle. When a bee lands on one of these, the disc adheres to its legs, and the pollinium is detached from the flower when the bee flies away. When the bee visits another flower, the flower is pollinated by the adhering pollinium on the bee. ;SpeciesThe Plant List, genus ''Calotropis''
/ref> # ''

Calotropis acia ''Calotropis'' is a genus of flowering plants in the family Apocynaceae, first described as a genus in 1810. It is native to southern Asia and North Africa. They are commonly known as milkweeds because of the latex they produce. ''Calotropis'' ...

'' Buch.-Ham. - India # ''

Calotropis gigantea ''Calotropis gigantea'', the crown flower, is a species of ''Calotropis'' native to Cambodia, Vietnam, Bangladesh, Indonesia, Malaysia, Thailand, Sri Lanka, India, China, Pakistan, and Nepal. It is a large shrub growing to tall. It has clus ...

'' (L.) Dryand. - China, Indian Subcontinent, Southeast Asia # ''

Calotropis procera ''Calotropis procera'' is a species of flowering plant in the family Apocynaceae that is native to North Africa, Pakistan,tropical Africa, Western Asia, South Asia, and Indochina. The green fruits contain a toxic milky sap that is extremely bi ...

'' (Aiton) Dryand. - China, Indian Subcontinent, Southeast Asia, Middle East, North Africa ;formerly included ''Calotropis sussuela'', synonym of ''

Hoya imperialis Hoya may refer to: Places *Hoya, Germany, a city in Lower Saxony, Germany *County of Hoya, a former state in present Germany * Hoya, Tokyo, now incorporated within Nishi-tokyo, Tokyo, Japan * Hoya, Hpruso, a place in Hpruso Township, Kayah, Myanmar ...

Toxicity

The milky exudation from the plant is a corrosive poison. ''Calotropis'' species are poisonous plants;

calotropin Calotropin is a toxic cardenolide found in plants in the family ''Asclepiadoideae''. In extreme cases, calotropin poisoning can cause respiratory and cardiac failure. Accidental poisoning is common in livestock who have ingested milkweed. Calotrop ...

, a compound in the latex, is more toxic than

strychnine Strychnine (, , US chiefly ) is a highly toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, or absorbed through the eye ...

. Calotropin is similar in structure to two cardiac glycosides which are responsible for the cytotoxicity of ''

Apocynum cannabinum ''Apocynum cannabinum'' (dogbane, amy root, hemp dogbane, prairie dogbane, Indian hemp, rheumatism root, or wild cotton) is a perennial herbaceous plant that grows throughout much of North America—in the southern half of Canada and throughou ...

''. Extracts from the flowers of ''Calotropis procera'' have shown strong

cytotoxic Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells ...

activity. The extracts are also harmful to the eyes. Cattle often stay away from the plants because of their unpleasant taste and their content of

cardiac glycoside Cardiac glycosides are a class of organic compounds that increase the output force of the heart and decrease its rate of contractions by inhibiting the cellular sodium-potassium ATPase pump. Their beneficial medical uses are as treatments for co ...

Cultural significance

The flowers of the plant are offered to the Hindu deities

Shiva Shiva (; sa, शिव, lit=The Auspicious One, Śiva ), also known as Mahadeva (; ɐɦaːd̪eːʋɐ, or Hara, is one of the principal deities of Hinduism. He is the Supreme Being in Shaivism, one of the major traditions within Hindu ...

Ganesha Ganesha ( sa, गणेश, ), also known as Ganapati, Vinayaka, and Pillaiyar, is one of the best-known and most worshipped deities in the Hindu pantheon and is the Supreme God in Ganapatya sect. His image is found throughout India. Hindu d ...

, Shani Dev and Hanuman.

Gallery

File:ThoraThora1.JPG, ''

'' File:Starr_010503-9002_Calotropis_procera.jpg, ''Calotropis procera'' branch with flowers File:Starr 010701-9001 Calotropis procera.jpg, ''Calotropis procera'' fruit File:Calotropis procera.jpg, ''Calotropis procera'' File:Adrar-Calotropis procera (1).JPG, ''Calotropis procera'' File:Algodon de seda (Calotropis procera) 3.jpg, ''Calotropis procera'' File:Calotropis giganteaRHu3.JPG, ''

'' File:C. gigantea.JPG, ''Calotropis gigantea'' File:Starr 070730-7945 Calotropis gigantea.jpg, Floral tassels made from ''Calotropis'' flowers.

References

External links

USDA classification for ''Calotropis''

''Calotropis procera''

{{Taxonbar, from=Q310216 Asclepiadoideae Apocynaceae genera Taxa named by Robert Brown (botanist, born 1773) Poisonous plants