Euphorbia myrsinites, the myrtle spurge,<ref name=GRIN>Template:GRIN</ref> blue spurge,<ref name=GRIN/> or broad-leaved glaucous-spurge,<ref name=BSBI07>Template:Cite web</ref> is a succulent species of the spurge (family Euphorbiaceae).
The specific epithet myrsinites is derived from the Greek word Template:Lang (myrsinites), which was used in Dioscorides's De Materia Medica to describe its similarity to Template:Lang (myrsine), aka myrtle (Myrtus communis). In other contexts, the word could be used to describe a similarity to Myrsine, another unrelated genus whose name is also derived from the Greek name of myrtle.<ref>Template:Cite book</ref><ref>Template:Cite book</ref>
Myrtle spurge is an evergreen perennial. It has sprawling stems growing to 20–40 cm long. The leaves are spirally arranged, fleshy, pale glaucous bluish-green, 1–2 cm long. The flowers are inconspicuous, but surrounded by bright sulphur-yellow bracts (tinged red in the cultivar 'Washfield'); they are produced during the spring.<ref name="rhs">Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Template:ISBN</ref>
Plants spread primarily by seed and are capable of projecting seed up to 15 feet.<ref>Template:Cite web</ref>
The plant's milky sap can cause significant skin and eye irritation in humans. Goggles, gloves and protective gear is often used when removing plants. Children are more susceptible than adults to symptoms from myrtle spurge, suggesting play areas not in proximity to the species. Pets can have similar reactions to myrtle spurge sap exposure.
The species can be strongly allelopathic, preventing other plants from growing nearby.
Euphorbia myrsinites is cultivated as an ornamental plant for its distinctive silver-gray foliage, and is used in garden borders, 'modernist' mass plantings, and as a potted plant. It is planted in drought tolerant gardens in California and other dry climates.
Euphorbia myrsinites is identified as a noxious weed and/or invasive species in some regions. Its cultivation is illegal in the U.S. state of Colorado, where it is classified as a Class A noxious weed, and landowners are legally required to eradicate it.<ref>Myrtle Spurge</ref>
It was listed as a noxious weed in Salt Lake County, Utah in 2007, and since has been illegal for sale within the county.<ref>Salt Lake County Weeds</ref> Salt Lake County landowners and land managers are legally responsible to contain, control, or eradicate the species on their property. The Utah Native Plant Society has also formally recommended it be listed as a Utah state noxious weed.
- Physical control
- Small infestations can be controlled through multiple years of digging up at least 4" of the root. Myrtle spurge is best controlled in the spring when the soil is moist and prior to seed production. Make sure to dispose of all the plant parts in the garbage instead of composting.<ref>Template:Cite web</ref>
- Chemical control
- Myrtle spurge can be effectively controlled with products containing 2, 4-D and dicamba (i.e. Weed B Gon) applied in late fall.<ref>Template:Cite web</ref>
- Biological control
- There are currently no known bio-controls, though the leafy spurge flea beetle (Aphthona), has had a high survival rate on myrtle spurge in laboratory studies.<ref>Template:Cite web</ref>