Toothed spurge

Toothed spurge - Euphorbia dentata Michx.

Family: Euphorbiaceae (Spurge family)
Life cycle: Annual
Habitat: Crop fields, waste areas.

General description: Erect plants reaching heights of 2 ft. Leaves are highly variable, ovate to lanceolate, up to 3 in long, with a dentate margin. Occasionally, leaves will have purple spots. Leaf margins shallowly to coarsely toothed, pubescent on both sides. Leaves may be opposite or alternate, and sometimes have purple spots. A cluster of green flowers is produced at the end of stems, developing into three-lobed, rounded fruit. Milky sap from leaves and stems.

Key ID traits: Milky sap; toothed leaves.

Similar species: Wild poinsettia is very similar to toothed spurge, but its leaves are shinier and turn red at the base.

Miscellaneous: Toothed spurge was first noted as a significant problem in the mid-1980’s following the introduction of the ALS-inhibiting herbicides. Problems with this weed have diminished since the introduction of Roundup Ready crops.

cluster of three-lobed capsules at terminal end of branches
Cluster of three-lobed capsules at terminal end of branches
erect, branched growth habit with dentate leaf margins
Erect, branched growth habit with dentate leaf margins