Euphorbia heterophylla

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids I
Ordo: Malpighiales

Familia: Euphorbiaceae
Subfamilia: Euphorbioideae
Tribus: Euphorbieae
Subtribus: Euphorbiinae
Genus: Euphorbia
Subgenus: E. subg. Chamaesyce
Sectio: E. sect. Poinsettia
Subsectio: E. subsect. Stormieae
Species: Euphorbia heterophylla
Varietates: E. h. var. cyathophora – E. h. var. heterophylla
Name

Euphorbia heterophylla L., 1753
Synonyms

Homotypic
Tithymalus heterophyllus (L.) Haw., Syn. Pl. Succ.: 141 (1812).
Cyathophora heterophyla (L.) Raf., Fl. Tellur. 4: 117 (1838).
Poinsettia heterophylla (L.) Klotzsch & Garcke, Monatsber. Königl. Preuss. Akad. Wiss. Berlin 1859: 253 (1859).
Euphorbia heterophylla var. genuina Boiss. in A.P.de Candolle, Prodr. 15(2): 72 (1862), not validly publ.

Homonyms

Euphorbia heterophylla Desf., nom. illeg. = Euphorbia terracina L.

Distribution
Native distribution areas:
References
Primary references

Linnaeus, C. 1753. Species plantarum, exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas. Tomus I. Pp. [I–XII], 1–560. Impensis Laurentii Salvii, Holmiae [Stockholm]. BHL Reference page. : 453.

Links

Govaerts, R. et al. 2020. Euphorbia heterophylla in World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2020 Jun 30. Reference page.
International Plant Names Index. 2020. Euphorbia heterophylla. Published online. Accessed: Jun 30 2020.
Govaerts, R. et al. 2020. Euphorbia heterophylla in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2020 Jun 30. Reference page.
Tropicos.org 2020. Euphorbia heterophylla. Missouri Botanical Garden. Published online. Accessed: 30 Jun 2020.
USDA, ARS, Germplasm Resources Information Network. Euphorbia heterophylla in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 08-Apr-12.

Vernacular names
español: Corazón de María, Casalina, Catalina en Jalisco
日本語: ショウジョウソウモドキ
ไทย: ลูกเขยตายแม่ยายทำศพ

Euphorbia heterophylla, also known under the common names of (Mexican) fireplant,[2] painted euphorbia,[2] Japanese poinsettia,[2] desert poinsettia, wild poinsettia, fire on the mountain, paintedleaf,[2] painted spurge,[2] milkweed,[2] and kaliko plant, is a plant belonging to the Euphorbiaceae or spurge 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.[3]

This plant has been introduced to South and Southeast Asia as an ornamental plant, having become a weed in India and Thailand, where it has invaded cotton fields and other agricultural terrain. [4]
Description
Euphorbia heterophylla after losing coloration of its cyathia

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.[5]

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.[5]

The stalk exudes a toxic milky white latex. 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.[3]

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.[6]
Toxicity

Toxicity is documented in most members of the genus Euphorbia. Individuals sensitive to latex are known to have strong reactions, including dermatitis and anaphylaxis, to the latex exuded by this plant.
As a weed

E. heterophylla has developed herbicide resistance against fomesafen and imazethapyr in its native Brazil.[7]
References

"The Plant List: A Working List of All Plant Species".
"Euphorbia heterophylla". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 10 January 2018.
Wilson, A. K. (1981). "Euphorbia heterophylla: a Review of Distribution, Importance and Control". Tropical Pest Management. 27 (1): 32–38. doi:10.1080/09670878109414169. ISSN 0143-6147.
"Euphorbia heterophylla (wild poinsettia)". CABI invasive species compendium. Retrieved 30 December 2021.
"Plant Production and Protection Division: Euphorbia heterophylla". www.fao.org. Retrieved 2018-07-17.
Herbicide Resistant Weeds
Brusamarello, Antonio P.; Oliveira, Paulo H.; Trezzi, Michelangelo M.; Finatto, Taciane; Pagnoncelli, Fortunato D. B.; Vidal, Ribas A. (2020). "Inheritance of fomesafen and imazethapyr resistance in a multiple herbicide‐resistant Euphorbia heterophylla population". Weed Research. Wiley. 60 (4): 278–286. doi:10.1111/wre.12425. ISSN 0043-1737.