Euphorbia heterophylla, Mexican Fireplant, Southwest Desert Flora

Euphorbia heterophylla, Mexican Fireplant

Mexican Fireplant “flowers” are actually floral parts modified into a Cyathium, singular Cyathia. Here you see the fruits which are 3-lobed hairless capsules. The Cyathia are solitary or clustered on terminal stems. Euphorbia heterophylla

Mexican Fireplant leaves are bright green on the surface, bottoms are pale green. Euphorbia heterophylla Leaf shapes highly variable from linear to ovate, obovate, elliptic or lanceolate.

Mexican Fireplant has many common names from Desert Poinsettia, Painted Euphorbia and Painted Spurge. Plants grow up to almost 3 feet tall but are usually much less. Euphorbia heterophylla

Mexican Fireplant is a plant native to tropical and sub-tropical America. Plants are light green with erect stems. Branches ascend upward from near base and plants mostly hairless. Euphorbia heterophylla

Scientific Name: Euphorbia heterophylla
Common Name: Mexican Fireplant

Also Called: Desert Poinsettia, Japanese Poinsettia, Mexican-Fireplant, Painted Euphorbia, Painted Spurge, (Spanish: Picachalih)

Family: Euphorbiaceae, Spurge or Euphorbia Family

Synonyms: (Euphorbia cyathophora, Euphorbia geniculata, Euphorbia heterophylla var. eriocarpa, Euphorbia heterophylla var. graminifolia, Euphorbia prunifolia, Poinsettia geniculata, Poinsettia heterophylla)

Status: Native to tropical and sub-tropical America; now observed throughout the tropics and has spread rapidly in many parts of the world. Introduced to South and Southeast Asia as an Ornamental, apparently a weed in India and Thailand invading cotton fields and agricultural terrain.

Duration: Annual

Size: Up to 36 inches or usually much less; (30-90 cm)

Growth Form: Forb/herb; light green stems erect, branches ascending from near base, plants mostly hairless.

Leaves: Bright green adaxially, pale green abaxial; lower leaves mostly alternate, leaf shapes highly variable from linear to ovate, obovate, elliptic or lanceolate; leaf petiole slender at first and widening near leaf blade; leaf margins typically entire and may be lyrately lobed.

Flower Color: Flora leaves (bracts) are often partly colored pink or red; , "flowers" are a cyathium, singular cyathia are clustered terminally; fruits are 3-lobed glabrous capsules

Flowering Season: August to September or October.

Elevation: 2,500 to 5,000 feet - (762-1524 m)

Habitat Preferences: Margins of streams, washes and hillsides and in open or wooded, disturbed areas, usually in sandy soil.

Recorded Range: Euphorbia heterophylla is found in the southern half of North America from southern California east to Georgia and Florida; and southern through Mexico to South America. It is also found in Africa, Asia, Europe and Australia.

North America & US County Distribution Map for Euphorbia heterophylla.

U.S. Weed Information: In North America Euphorbia heterophylla (and as E. prunifolia - Painted Euphorbia) can be weedy or invasive according to the following authoritative sources: Southern Weed Science Society 1998. Weeds of the United States and Canada.. Southern Weed Science Society. Champaign, Illinois; and in other states by assorted authors. State noxious weed lists for 46 states. State agriculture or natural resource departments. Plants included here may become weedy or invasive.

Invasive/Noxious Weed Information: In North America Euphorbia heterophylla is listed as a Noxious Weed by the states of Florida (as E. prunifolia - Painted Euphorbia) and South Caroline (as E. prunifolia - Painted Euphorbia) to be a plant pest. Plants included here are invasive or noxious.

Wetland Indicator: In North America Euphorbia heterophylla has the following wetland designations: Arid West, UPL; Atlantic and Gulf Coastal Plain, FAC; Eastern Mountains and Piedmont, FACU; Great Plains, FACU ans Western Mountains, Valleys, and Coast UPL.
FAC = Facultative, occur in wetlands and non-wetlands
FACU = Facultative Upland, usually occur in non-wetlands, but may occur in wetlands
UPL = Obligate Upland, almost never occur in wetlands.

Threatened/Endangered Information: No information available.

Genus Information: In North America there are hundreds of species and even more accepted taxa overall for Euphorbia. Worldwide, The Plant List includes 2,031 accepted species names and a further 1,322 scientific names of infraspecific rank for the genus.

In the Southwestern United States: Arizona has 21 species of genus Euphorbia, California has 25 species, Nevada has 6 species, New Mexico has 22 species, Texas has 31 species, Utah has 12 species. All data is approximate and subject to taxonomic changes.

Comments: The genus Euphorbia is large with more than 2,000 species worldwide. In the southwest there are about 30 species or so. As with many species of Euphorbia, this species releases a milky sap of white latex which is toxic.

In Southwest Desert Flora also see Euphorbia eriantha, Beetle Spurge, Euphorbia incisa, Mojave spurge and Euphorbia radians, Sun Spurge.

Etymology: The genus Euphorbia is named for a Greek physician, Euphorbus of Juba II, King of Mauretania. The species epithet "heterophylla" is derived from both Latin and Greek; from Latin "heterophylla" is inflected form of heterophyllus meaning “different forms of leaves” on a single plant; a reference to the highly variable leaf shapes of this species.

Ethnobotany No information available.