''Euphorbia heterophylla'', also known under the

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

s of Mexican fireplant, painted euphorbia, Japanese poinsettia, paintedleaf, painted spurge and milkweed, is a plant belonging to the Euphorbiaceae or

spurge ''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to t ...

family.

Distribution

''Euphorbia heterophylla'' is native to tropical and subtropical America but is now widespread throughout the tropics. Many herbicides fail to control it and hence it has spread rapidly in many parts of the world. This plant has been introduced to

South South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...

and

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 ...

as an

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

, having become a weed in

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

and

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...

, where it has invaded cotton fields and other agricultural terrain.

Description

Zebra Blue (Leptotes plinius) on Euphorbia heterophylla (Painted Euphorbia) W2 IMG 9734

Euphorbia heterophylla grows between 30 and 100 cm tall and has hollow stems that may be branched or simple with angular ribs. The leaves of the plant have variable shapes within and between populations. The lower leaves are alternate whereas the upper leaves are opposite and commonly have a whitish or bright red base. Within 30 days of emergence the plant may flower with ripe seeds being formed between 25 and 30 days later. It is pollinated by insects which are attracted to large amounts of nectar the plant produces. The stalk exudes a toxic milky white

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 ...

. The cyathia or false flowers, are located in clusters at the head of the stalk and are yellowish green. They have no petals, the red color being part of the young leaves' coloration. The fruits are small, segmented capsules. When the fruits are mature, they explode and shoot the seeds some distance from the parent plant allowing the plant to disperse. This plant often loses its coloration when it grows wild as a weed. There are populations that have been identified to have resistance to specific herbicides in South America.

Toxicity

Toxicity is documented in most members of the genus

Euphorbia ''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to t ...

. Individuals sensitive to

are known to have strong reactions, including

dermatitis Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can v ...

and

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follow ...

, to the latex exuded by this plant.

As a weed

''E. heterophylla'' has developed

herbicide resistance Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...

against

fomesafen Fomesafen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to fomesafen, via m ...

and imazethapyr in its native

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

References

External links

USDA Plants Profile for ''Euphorbia heterophylla'' (Mexican fireplant)
{{Taxonbar, from=Q3060418 heterophylla Flora of Central America Flora of the Caribbean Flora of Mexico Flora of the Southeastern United States Flora of northern South America Flora of southern South America Flora of western South America Flora of Brazil Flora of Florida Flora of Texas Flora of the Yucatán Peninsula Ruderal species Plants described in 1753 Taxa named by Carl Linnaeus Flora without expected TNC conservation status