Myrtle spurge

Euphorbia myrsinites

Keys to Identification

Myrtle spurge has recently been designated as a "A" listed noxious weed by Colorado. This perennial weed is often found in rock gardens and is moving into natural areas where it has the potential to do enormous environmental damage.
Although easily removed by hand, this member of the spurge family (Euphorbiaceae), contains a milky sap that is caustic to skin and eyes.
Blue-green leaves clasp fleshy stems which trail along the ground. Inconspicuous yellow-green flowers are surrounded by heart shaped bracts

This information courtesy of the Colorado Natural Areas Program

Family: Euphorbiaceae (Spurge)

Other Names: creeping spurge, donkeytail

USDA Code: EUMY2

Legal Status: Colorado Noxious Weed List A

Identification

Lifecycle: Perennial

Growth form: Forb

Flower: Yellow-green flower-like bracts appear in early spring.

Seeds/Fruit: Hard, round

Leaves: The plant produces trailing stems of fleshy, blue-green alternate leaves.

Stems: Mature plants are 4-6 in tall and spread up to 18 in laterally.

Roots: Taproot.

Seedling: No information available.

Other: The plant exudes a milky sap that can be irritating to the skin.

Similar Species

Exotics: Non-flowering stems may sometimes be mistaken for Dalmatian toadflax.

Natives: None known.

Impacts

Agricultural: Myrtle spurge plants exude a milky sap that is considered toxic and may cause skin irritations and in extreme cases, livestock poisoning. Livestock and animals generally avoid myrtle spurge and large infestations can reduce forage production. Myrtle spurge does not tolerate frequent cultivation and therefore is not a problem in crops.

Ecological: Can inhabit disturbed ground and exclude native plants in remote rocky locations.

Human: Milky latex can cause minor skin irritation.

Habitat and Distribution

General requirements: Myrtle spurge prefers dry to moist, well-drained soils, in areas that receive partial shade to full sun. It is mainly an escaped ornamental that inhabits disturbed areas and waste places.

Historical: Native to Eurasia.

Biology/Ecology

Life cycle: Myrtle spurge is a perennial that produces new stems from the center (tap root) each year. Plants flower in early spring.

Mode of reproduction: Myrtle spurge reproduces by seed.

Integrated Management Summary

This species is not yet widespread in Colorado, and should be a priority for immediate eradication if found. As with other plants which reproduce solely by seed, integrated management efforts of myrtle spurge must include the elimination of seed production and the depletion of the seed bank. Combine herbicide or mechanical removal of rosettes with removal of flowering parts from any plants that have bolted.

References

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

Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 1996. Euphorbia spp. Weeds of the West. Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark CA. pg. 312.

CWMA