Species Information

• oblong spurge (eggleaf spurge)
• Euphorbia oblongata Griseb.
• USDA Symbol: EUOB4
• Oregon Noxious Weed Designation: A
• Pictures

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Identification:

Oblong spurge is a weedy escaped ornamental species of Euphorbia. This plant is an exotic perennial herb that produces up to 20 stems on a woody rootstalk with the plants reaching nearly three feet in height. The alternate, oblong leaves are glabrous (smooth and hairless) with finely toothed margins. Leaves and stems exude a milky sap when cut; skin contact should be avoided. Numerous yellowish-green bracts and flowers typical to most spurges develop at terminal tips. Seedpods have a waxy appearance, and when mature, ripened pods forcefully eject their seeds for localized dispersal.

Impacts:

In western Oregon this plant thrives in moist grassy bottomland even with significant competition. In other states, infestations appear to be spreading more aggressively, perhaps the result of it establishing on drier sites with little competition. Oblong spurge has a great capacity to infest riparian areas in Washington and Oregon. It is well adapted to a wide range of shrub and pine forest environments. In California it has been found associated with French broom, blackberry and in dry drainages along roadsides.

Biological Controls:

Biological control agents are not used on "A" listed weeds in Oregon. This weed is being managed for eradication or containment.

Oregon Maps of Oblong Spurge Distribution

Links:

Oregon Department of Agriculture information on oblong spurge

USDA Plants Database information on oblong spurge

GRIN Database information on oblong spurge