Euphorbia incisa, Mojave spurge, Southwest Desert Flora

Euphorbia incisa, Mojave spurge

Euphorbia incisa has green flowers modified into a “cyathium” in leafy bracts from leaf axils. The fruits, not shown here, are an oblong loved capsule. Mojave spurge

Euphorbia incisa blooms from February or March to May through August across its narrow geographic range. Mojave spurge

Euphorbia incisa grows up to about 16 inches or so and has smooth or slightly pubescent surfaces. The stems are often purplish, many and erect to falling over with continued growth upward. Mojave spurge

Euphorbia incisa is often found in small clusters on the shady side of slopes and on cliff surfaces as in this photo. Mojave spurge

Euphorbia incisa is often found in small clusters on shady slopes as in the photo and also on cliff surfaces as in the photo above. Mojave spurge

Scientific Name: Euphorbia incisa
Common Name: Mojave spurge

Also Called:

Family: Euphorbiaceae, Spurge or Euphorbia Family

Synonyms: (Euphorbia schizoloba, Euphorbia incisa var. incisa, Euphorbia incisa var. mollis, Tithymalus incisa, Tithymalus incisa var. mollis, Tithymalus schizolobus)

Status: Native

Duration: Perennial

Size: Up to 16 inches (35 to 40 cm)

Growth Form: Forb/herb; plants glabrous or slightly pubescent, stems purplish, many, erect to ascending or decumbent.

Leaves: Green alternate, usually sessile or with a short petiole (sub-sessile, blade shape variable, elliptical, to ovate, obovate or oblanceolate, margins entire, leaf tips rounded or pointed, highest leaves whorled.

Flower Color: Green; flowers monecious, in umbel-like cluster from leaf axils in whorled leaves, "flowers" modified into a cyathium in leafy bracts; fruit an oblong lobed capsule.
Flowering Season: February to August; March to May in California.

Elevation: 3,000-9,000 feet (900 - 2743 m);

Habitat Preferences: Rocky or sandy slopes; upper elevations, shady riparian areas; desert transitions and beyond.

Recorded Range: In North America Euphorbia incisa is found in the southwestern United States in AZ, CA, CO, NM and NV.

North America & US County Distribution Map for Euphorbia incisa.

U.S. Weed Information: No information available.
Invasive/Noxious Weed Information: No information available.
Wetland Indicator: No information available.
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 Arizona type species is from Cerbat Mountains, Mohave County (Newberry in 1858) Euphorbia incisa, Mojave spurge. The synonym E. schizoloba is disputed to be a separate species.

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 heterophylla, Mexican Fireplant 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 "incisa" is a reference to the deeply or irregularly cut floral parts.

Ethnobotany Euphorbia incisa, Mojave Spurge has been used to increase fertility and to increase fertility in livestock.

Navajo, Kayenta Drug, Gynecological Aid. Plant used to increase fertility in women.

Navajo, Kayenta Drug, Veterinary Aid. Plant used to increase fertility in livestock.

See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.