Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Chamaesyce albomarginata, Whitemargin Sandmat

Chamaesyce albomarginata, Whitemargin Sandmat, Southwest Desert Flora Chamaesyce albomarginata, Whitemargin Sandmat, Southwest Desert Flora Chamaesyce albomarginata, Whitemargin Sandmat, Southwest Desert Flora Chamaesyce albomarginata, Whitemargin Sandmat, Southwest Desert Flora

Scientific Name: Chamaesyce albomarginata
Common Name: Whitemargin Sandmat
Also Called: Rattlesnake Weed, Spurge, Whitemargin Eupatorium, Whitemargin Euphorbia, White-margin Sandmat, Whitemargin Spurge; (Spanish: Golondrina)
Family: Euphorbiaceae, Spurge or Euphorbia Family
Synonyms: (Euphorbia albomarginata)
Status: Native
Duration: Perennial;
Size: Up to 3 inches or more.
Growth Form: Forb/herb or annual; small and low-growing either prostrate to erect, forms mats, alternate branching, glabrous or hairy, milky sap, poisonous.
Leaves: Green, dusty green, variable; mostly opposite, leaves flat often with a white margin, petioles short, stipules united, asymmetric, round or heart shaped.
Flower Color: White petaloid appendages; appendages wider than glands (see photo), glands burgundy, inflorescence resembles a "flower", typically bell-shaped, solitary, actual flowers small or inconspicuous, botanically a cyathium which is one of the Euphorbiaceae reproductive strategies, monecious, fruit a capsule, round or angled.
Flowering Season: February to October.
Elevation: 1,000 to 6,000 feet, usually at lower elevations under 3,000 feet.

Habitat Preferences: Dry slopes, clay and loam or sandy soils, disturbed urban areas.

Recorded Range: Whitemargin Sandmat is found in the southwest United States, Baja California and northern Mexico. In the United States it is native to: AZ, CA, HI, LA, NM, NV, OK, TX and UT. In Arizona it occurs throughout most of the state, possibly absent in Yuma County.

North America & US County Distribution Map for Chamaesyce albomarginata.

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: Over 90 species in Chamaesyce in the United States, Canada and Mexico. World-wide over 440 species. Approximately 39 species in Arizona, statewide. Note: Taxonomists appear to be moving toward reclassification of Chamaesyce to Euphorbia, its former classification.

Comments: Whitemargin Sandmat is so named because it often has a thin white ringed margin on the leaf. Shoshoni Americans have used this plant as a snake bite remedy likely explaining one of its multiple common names; Rattlesnake Weed.

In Southwest Desert Flora also see: Chiricahua Mountain Sandmat, Chamaesyce florida, Arizona Sandmat, Chamaesyce arizonica; Head Sandmat, Chamaesyce capitellata; Royal Sandmat, Chamaesyce dioica; Hyssopleaf Sandmat, Chamaesyce hyssopifolia; Red-gland Sandmat, Chamaesyce melanadenia; Carrizo Mountain Sandmat, Chamaesyce pediculifera; Threadstem Sandmat, Chamaesyce revoluta and Yuma Sandmat, Chamaesyce setiloba.

Whitemargin Sandmat has been used as an analgesic by the Navajo, a gynecological aid by the Zuni and as a snake bite remedy by the Shoshoni. See complete list of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.

Date Profile Completed: 5/15/2015, rev. 07/22/2015, updated format 10/12/2017
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 06/19/2019)
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, California, as Euphorbia albomarginata.
Native Plant Information Network, NPIN (2013). Published on the Internet [accessed: 5/15/2015]. Lady Bird Johnson Wildflower Center at The University of Texas, Austin, TX.
1993, The Jepson Manual, Citation: (accessed 5/15/2015)
Wikipedia contributors, 'Euphorbia albomarginata', Wikipedia, The Free Encyclopedia, 12 May 2015, 16:44 UTC, [accessed 15 May 2015]
SEINet for synonyms, scientific names and recorded geographic locations,