Written findings of the

WASHINGTON STATE NOXIOUS WEED CONTROL BOARD

Listed  2003

 

Scientific Name: Euphorbia myrsinites L. synonym Tithymalus myrsinites L.

Common Name: Myrtle spurge, creeping spurge, or donkey tail spurge

amily: Euphorbiaceae (Spurge)

Legal Status:  Class C Weed for Washington State’s 2003 Noxious Weed list


Description and Variation: Myrtle spurge is a perennial forb with decumbent (spreading low to the ground) fleshy trailing stems. In early spring, new stems emerge from a central taproot. Mature plants are 4-6 inches tall spreading up to 18 inches laterally. Leaves are alternately arranged in close spirals around the stems, fleshy, and blue-green in color. The flowers, appearing in early spring, are inconspicuous and surrounded by a showy yellow green bract. Leaves, stems, and roots all exude a milky, irritating sap when broken (Turner, 1995).

 

Economic Importance:

Detrimental: myrtle splurge can inhabit disturbed ground crowding out native habitat for deer and other wildlife. It also poses dangers to children and adults who come in contact with its caustic latex sap. It causes nausea, vomiting, and diarrhea when ingested. Contact with the skin results in redness, swelling, and blisters (Russell et al. 2002).

Beneficial: This plant has been touted as a deer proof, xeriscape plant. It has also been noted as a hardy ornamental for gardens and is being sold as a hardy ornamental plant for dry, sandy locations.

 

Habitat: Myrtle spurge prefers well-drained dry to moist soils with partial shade to full sun. This plant is an escaped ornamental that inhabits disrupted areas and waste places. It is primarily found in municipal areas and near wild lands (Personal contact, Boulder County Colorado).

 

Geographic Distribution: Grows well in Zones 5-9 and is known to inhabit dry rocky areas.

 

History: Myrtle spurge is native to Eurasia, historically it is thought to be native to the Mediterranean regions ranging from the Balearic Islands throughout parts of Italy. It was brought to the United States as an ornamental.

 

Growth and Development: In early spring, new stems emerge from a central taproot. Myrtle spurge flowers in early spring (March and April). The "flower" color ranges from a yellow to a dull pink. The foliage dies back during the winter months.

 

Reproduction: Myrtle spurge is typically spread by seed. It is noted that roots fragmented by cultivation can produce new plants.

 

Response to Herbicide: 2,4-D or dicamba at 1 lb/acre, and glyphosate at 1.5 lb. Ai/acre should provide adequate control. Application of herbicides should be done selectively to avoid damage to non-target species. The best time to treat myrtle spurge is during late fall, (Stahevithch et al. 1996).

 

Response to Cultural Methods: None known

 

Response to Mechanical Methods: Small infestations can successfully be dug or pulled. In order to gain some control over a population it must be pulled over multiple years. Use caution when pulling to not get any sap on your skin. If sap encounters skin make sure to wash the area of contact.

 

Biocontrol Potentials: None known

 

Rationale for Listing: Grant County has an escaped ornamental population that has proven to be difficult to control. Grant County has reports of children developing rashes after handling this plant and is concerned that this species may continue to spread without aggressive management measures. Due to the aggressiveness of the plant, and the aggressive nature of other spurge species, Grant County has asked that we list myrtle spurge to enable them to begin control measures. This species has also been noted in Pend Oreille County. Currently the plant is listed as a noxious weed in Colorado.

References:

Migahid M. A., M. A.,Elhaak Jun 2001, Ecophysiological studies on some desert plant species native to the Mediterranean area in Egypt Journal of Arid Environments, Vol. 48, No. 2, pp. 191-203

Stahevitch, A.E, C.W. Compton, and W.A. Wojtas. 1996. The biology of Canadian weeds. 85. Euphorbia cyparissias L. Canadian Journal of Plant Science 68:175-191

Turner R. 1995, Euphorbias A Gardners’ Guide, Timber press Portland OR, p.133-136

Russell A.B., J.W. Hardin, L. Grand, A. Graser, 2002 "Poisonous Plants of North Carolina," North Carolina Cooperative Extension Service, North Carolina State University

Web pages of significance:

URL: http://www.gis.usu.edu/Geography-Department/utgeog...

URL:http://www.ces.ncsu.edu/depts/hort/consumer/poison...

URL: http://www.nargs.org/gardening/Euphorbia.myrsinite

URL:http://www.co.boulder.co.us/openspace/resources/weeds/weeds%5Fconcern.htm#