Chamaesyce albomarginata, Whitemargin Sandmat
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)
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.