Family: Spurge (Euphorbiaceae)
Size: Tiny, to 0.125 in.
Other names: White margin spurge, whitemargin sandmat.
Notes: Perennial herb. Reproduces from seed or by putting down roots where joints hit ground. Milky sap may irritate skin. More than 3 dozen species of Euphorbia in Arizona.
Spurges entry in the online edition of An Illustrated Guide to Arizona Weeds, Kittie F. Parker, University of Arizona Press.
This plant is found on the Appleton-Whittell Research Ranch Working Check list of flora.
Rattlesnake weed plant profile on the USDA Plants server.