Euphorbia cyparissias L.
Cypress spurge is a member of the Euphorbiaceae or spurge family. It is a rhizomatous-root-spreading perennial that is generally shorter than 6 inches. It has narrow, linear leaves ranging from ½ inch to 1 ¼ inches long. Like most spurges, its leaves are waxy. The flowers are bright yellow and turn red-brown as the plant matures. It contains waxy latex that can cause rashes and irritation in humans, wildlife, and domestic animals.
Cypress spurge is an introduced species originating from Europe. It was likely introduced into the U.S. as an ornamental. In Teton County, this plant has been found escaping at a local cemetery. It is most likely to spread through aggressive lateral roots, and to the lesser extent via seed.
Control of this species may be difficult due to the reduced leaf surface area and waxy cuticle layer on the leaves and stem; however, success is likely due to its low seed viability. Cypress spurge does not appear to be as aggressive as leafy spurge, but is still considered a threat.
If you find this weed on your property or around Teton County, please report it immediately at 733-8419.