This erect, native annual grows up to 2 feet tall; the stems contain a milky juice (D). The mostly alternate leaves are highly variable. Some are long and narrow as shown in (B), but they often are broader and deeply lobed or fiddle-shaped (C). Modified upper leaves (leaf-like bracts) , often with bright red or yellowish blotches near the base, surround several inconspicuous floral cups (cyathia) typical of the spurges. Each cup holds 1 female and 30-50 yellow male flowers (A,E). The fruit is a rounded 3-lobed capsule which projects beyond the rim of the cup (E).

When present, the red color of the leafy bracts is diagnostic. Toothed Spurge (Euphorbia davidii) has pale white upper leaf bases and its leaves are mostly opposite.